Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

## 1 Onroad Mobile Sources and Vehicle Refueling (Stage 2) Onroad mobile source emissions are those gene rated by operating vehicles on public roadways. Emissions from fuel combustion and evaporati on were estimated. Emissions from vehicle refueling were estimated for 2015. SWCAA had already estimated emissions from vehicle refueling for 2002.

1.1 Activity Level and Spatial Allocation 

### The activity measurement for onroa d mobile sources is the number of miles driven. The units are typically given in averag e daily vehicle miles traveled (ADVMT). ADVMT is normally estimated from traffic counts collected over a sampling area, or through use of travel demand models, which simulate vehicle travel patterns based on demogr aphic and economic parameters and are validated w ith traffic counts.

For this inventory, Clark C ounty ADVMT was obtained from the Southwest Regional Transportation Council (RTC). 1, 2 

### RTC provided VMT for 1996-2000 and 2015. ADVMT was provided by roadway link (approx 7000), road cl ass, speed, and Inspection and Maintenance program. A vehicle Inspection and Maintenanc e (I/M) program is ope rated in the greater Vancouver area of Clark County.

1.2 Temporal Allocation 

### ADVMT was not provided for 2002. The growth f actor from 2000 to 2002 was calculated based on linear interpolation of ADVMT for 2000 and 2015. The calculated factor was 1.042. This factor was used to grow the link-level 2000 ADVMT to 2002.

ADVMT also had to be seasonally adjusted. WSDOT provided monthly ADVMT adjustment factors for the 1990 carbon monoxide and ozone nonatt ainment area base year inventory efforts (Table 2). 3 

### The factors were compared to similar data for 1994 4 

### and showed very little change. WSDOT calculated the factors for two road classe s: Interstates, and non- Interstates. The RTC Interstate and Ramp road classes were assigne d to the WSDOT Interstate class, and the RTC Arterial, Local and Intrazonal cl asses were assigned to the WS DOT non-Interstate class. ADVMT was multiplied by the adjustment factors fo r July to estimate average ozone season day VMT. The WSDOT adjustment factors we re multiplied by the ADVMT estimates and the average number of days per month to estimate to tal monthly VMT, which in turn was used in the annual emissions calculations. ADVMT estimates are shown in Table 3.

Table 1: Estimated 2002 ADVMT

Year ADVMT 2000 6,725,065 2015 8,857,114

2002 est 7,009,338Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### Table 2: WSDOT Monthly VMT Adjustment Factors
Adjustment Adjustment Month Freeway Arterial/Local Month Freeway Arterial/Local Jan 0.878 0.914 Jul 1.083 1.061 Feb 0.896 0.947 Aug 1.114 1.077 Mar 0.963 1.001 Sep 1.044 1.013 Apr 0.997 1.020 Oct 1.020 0.987 May 1.013 1.024 Nov 0.975 0.950 Jun 1.057 1.065 Dec 0.959 0.942



### Table 3: Clark County ADVMT, 2002

I/M Area Arterial Interstate Intrazonal Local Ramp TOTAL Ozone season day No 817,415 914,020 8,815 207, 697 12,124 1,960,072 Yes 3,412,544 1,460,390 10,673 387,966 257,034 5,528,606 Total 4,229,959 2,374,410 19,488 595,663 269,158 7,488,678 Annual No 281,312,517 308,224,823 3,033,829 71,478,747 4,088,456 668,138,372 Yes 1,174,423,302 492,470,909 3,673,019 133,517,993 86, 676,647 1,890,761,869 Total 1,455,735,818 800,695,732 6,706,848 204,996,740 90, 765,103 2,558,900,241



### Table 4: Clark County ADVMT, 2015

I/M Area Arterial Interstate Intrazonal Local Ramp TOTAL Ozone season day No 1,204,664 1,208,828 3,533 320,164 18,369 2,755,558 Yes 4,186,454 1,751,667 3,693 465,401 301,257 6,708,472 Total 5,391,118 2,960,495 7,226 785,565 319,626 9,464,030 Annual No 414,583,776 407,639,539 1,215,969 110,184,193 6,194,280 939,817,756 Yes 1,440,763,683 590,695,098 1,270,782 160,167,252 101, 589,554 2,294,486,369 Total 1,855,347,459 998,334,636 2,486,751 270,351,445 107, 783,834 3,234,304,125

1.3 Emission Rates: MOBILE6.2 

### Emission rates in grams per mile were generated using the EPA model MOBILE6.2. 5 

### Emission rates were generated for unique combinations of: month, facility type , vehicle type, speed, pollutant, and I/M area.

Local data was used for the following input parameters: evaluati on month, registration distribution, temperature, humid ity, inspection and maintenance (I /M) program, speed, facility type, and fuel parameters for Reid vapor pressure (RVP). The parameters are described below.

1.4 Evaluation Month 

### The MOBILE model can calculate emission factors th at represent a January 1 or July 1 fleet. The evaluation month affects the age of the fleet (and how reformulated gas is modeled when applicable). Reformulated gas does not apply in Washington, therefor e the evaluation month only affects fleet age. Emissions for January through March were calcula ted with the January 1 setting. The remaining months were calculated with th e July 1 setting.Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 1.5 Registration Distribution 

### Washington has a substantially olde r fleet than the national average. To model the effect of the older fleet, local data from the Washington Stat e Department of Licensing (DOL) was used to calculate the July 1 vehicle age registration distribution. 6 

### Because DOL does not register all transit and school buses, alternate sources of information were obt ained. Transit bus data came from Federal Transit Admini stration Annual Report data. 7 

### For school buses, the Puget Sound Clean Air Agency provided a spreadsheet of all Washington school bus es in use in 2001, 8 

### and the Washington State Office of the Superintendent of Public Instructi on supplied data for 2004. 9 

### Distributions were assigned to evaluation years as shown below.

Table 5: Registration Distribution Assignments Type Evaluation Years Year of Data Source 2002 2002 DOL vehicles except buses 2015 2004 (most recent) DOL 2002 2002 FTA transit buses 2015 2003 (most recent) FTA 2002 2001 data via PSCAA school buses 2015 2004 (most recent) OSPI

1.6 VMT Fractions 

### The VMT mix is the percentages of VMT alloca ted to each individua l vehicle type. The MOBILE6.2 model contains default mixes fo r each evaluation year between 1972 and 2020. The default light duty mix shows a decreasing trend in the amount of VMT assigned to cars relative to trucks/SUVs (68% in 1975 decreasing to 28% in 2020). In 2004, the default and the Washington sales data were fairly similar in the split between cars and trucks, although the individual truck type allocations were more heav ily weighted toward the heavier classes in the Washington distribution. Statistics show that nationally, light tr uck/SUV sales have outpaced the sale of cars prior to 200 4; however, the most recent sales ye ar data (2004) i ndicate that cars outsold trucks/SUVs. 10



### For 2002, the national default mix was used. Due to the uncertainty of th e future sales mix, it was decided to make use of the 2004 Washi ngton sales mix for the years 2004 and beyond, including the 2015 projection. The national defau lt split between heavy and light duty vehicles was retained (as well as the individual heavy dut y vehicle class allocati ons), and the individual light duty class allocations fo r Washington were slightly adju sted by normalizing them to the overall default allocation for light duty vehicl es. Light duty allocatio ns are shown below.

Table 6: Comparison of 2004 Default and Washington Light Duty VMT Mixes

LDV LDT1 LDT2 LDT3 LDT4 Default 0.4365 0.0752 0.2503 0.0771 0.0355 Washington 0.4486 0.078 1 0.1972 0.1031 0.0475



### Table 7: 2004 Default Heavy Duty and Motorcycle VMT Mix

HDV2B HDV3 HDV4 HDV5 HDV6 HDV7 HDV8A HDV8B HDBS HDBT MC

0.0386 0.0038 0.0030 0.002 3 0.0085 0.0101 0.0111 0. 0394 0.0019 0.0009 0.0058Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 1.7 Temperature and Humidity 

### Meteorological and fuel parameters are necessary to calculate emissions from both onroad and nonroad sources.

Temperatures for 2002 were taken from the Va ncouver 4NNE meteorological station for each month to be used in the annual inventory calculations for 2002 and 2015. 11 

### Temperatures for the typical ozone season day were calculate d according to EPA guidance for prior attainment/maintenance plan efforts. 12, 13, 14 

### The model requires minimum, maximum and ambient temperature. Ambient temperature is defined as: {min + [2/3 x (max-min)]}.

Because information required to calculate aver age monthly humidity values for 2002 were not readily available, long-term average (1961-1990) humidity and pressure from Portland International Airport was used to devel op the MOBILE6 input humidity parameters. 15 

### The humidity value required in MOBILE6 is a mixing ratio in mass of water vapor per unit mass of dry air. A calculation formula based on rela tive humidity, temperature and pressure was distributed with MOBILE6. 16



### Temperatures and humidity are shown in Table 8.

1.8 Reid Vapor Pressure (RVP) 

### Because of the proximity to Portland, Clark County gasoline was assumed to follow Portland RVP requirements. Portland summertime limits are 9.0 psi for May and 7.8 psi for June – Sept. 17 

### When using legal limits to calculate su mmertime RVP, EPA guidance and Ecology staff recommend calculating a safety margin. 18, 19 

### Accordingly, a calculated safety margin of 0.3 psi was applied to the period 2 (1992) RVP legal li mit of 9.0 psi, bringing the May RVP value to 8.7 psi. RVPs for the remaining months were taken from the 2002 fuel survey done by the American Automobile Manufacturers (AAM) and made av ailable through the Western Regional Air Partnership (WRAP). 20, 21 

### Fuel parameters are shown in Table 8.Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### Table 8: Meteorological and Fuel RVP Pa rameters used in the MOBILE6.2 and/or NONROAD models
Temperature Month minimum maximum ambient Humidity *RVP

Ozone day 61 98 86 86 7.8

Monthly and Seasonal Jan 34.5 44.8 41.4 24 14.3 Feb 33.2 51.7 45.5 26 12.4 Dec 35.4 48.8 44.3 25 14.3 Winter 34.4 48.4 43.7 25 14.3 Mar 34.3 51.0 45.4 29 12.4 Apr 40.0 59.5 53.0 32 12.4 May 43.5 64.5 57.5 40 8.7 Spring 39.3 58.3 52.0 34 12.4 Jun 49.9 73.8 65.8 49 7.8 Jul 54.5 80.1 71.6 55 7.8 Aug 51.9 80.2 70.8 64 7.8 Summer 52.1 78.0 69.4 56 7.8 Sep 45.5 76.4 66.1 49 7.8 Oct 38.6 63.1 54.9 39 9.8 Nov 35.7 55.2 48.7 31 12.4 Fall 39.9 64.9 56.6 40 12.4 * maximum monthly value selected for season
1.9 Inspection and Maintenance (I/M) Program 

### A Vehicle Inspection and Maintenance (I/M) prog ram is operated in the greater Vancouver area of Clark County. Input parameters have b een tracked to allow m odeling of the program. 22, 23, 24



### MOBILE6.2 allows specification of up to seve n I/M record sets to define an overall I/M
program. 25 

### The program could be captured using six I/M record sets as shown in Table 9.

Table 9: I/M Program Parameters

Parameter set 1 set 2 set 3 set 4 set 5 set 6 Prog Start Yr 1993 1998 1993 2002 1993 1998 Prog End Yr 2050 2050 2050 2050 2050 2050 Test Freq biennial biennial biennial biennial biennial biennial Program Type test only test only test only test only test only test only Test Type ASM 2525 phase-in* gas cap OBD exhaust ** OBD Evap + gas cap** 2500/idle gas cap

Model Yrs 1968-1995 1968-1995 1996- 2050 1996-2050 1968-2050 1968-2050 Vehicle Types light duty gasoline light duty gasoline light duty gasoline light duty gasoline heavy duty gasoline heavy duty gasoline Stringency 36% n/a 36% n/a 36% n/a Compliance 93% 93% 93% 93% 93% 93% Waiver pre-81 4% 4% 4% 4% 4% 4% Waiver 1981+ 7% 7% 7% 7% 7% 7% Exempt Age 25 yrs 25 yrs 25 yrs 25 yrs 25 yrs 25 yrs Grace Age 5 yrs 5 yrs 5 yrs 5 yrs 5 yrs 5 yrs Tech Training yes yes yes yes yes Yes * ASM = acceleration simulation mode ** OBD = on-board diagnosticsPrepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 1.10 Road Class (Facility Type) and Speed 

### The MOBILE6.2 model generates emission rates fo r four road classes: Interstate (without ramps) 26 

### , Ramps, Arterials, and Locals. All of the RTC road links had both road class and speed values. In MOBILE6.2, only Inters tates and Arterials allow user speed input. To make use of the speeds provided by RTC for Local roads, they were assigned to the MOBILE6.2 Arterial class. RTC Ramps were assigned to the MOBI LE6.2 Ramps class even though this meant that the RTC speeds could not be utilized. This was done in order to take advantage of MOBILE6.2’s unique driving cycle for Ramps. Ramps have a high acceleration driving cycle which cannot be captured in any other class, an d acceleration affects emis sion rates. All road class assignments are shown in Table 10.

Table 10: MOBILE6.2 Road Class Assignments

RTC Class MOBILE6.2 Class Interstate Interstate Ramp Ramp Arterial Arterial Local Arterial Intrazonal Arterial



### Speeds were not included in the 2000 ADVMT file from RTC, but they were available in the 2015 file. Speeds for 2000 were assigned by matching individual links to the 2015 ADVMT file by link ID number. The lesser of the morning, evening and off-peak link speeds for 2015 were assigned to the 2000 links. Links for 2000 which had no match in the 2015 file were assigned the average 2015 speed for the li nk’s road class. Neither th e 2000 nor the 2015 file included speeds for the Intrazonal class li nks. An average speed of 15 m ph was assigned to these links.

1.11 Vehicle Refueling (Stage 2) Parameters 

### It was assumed that the current at-the-pump st age 2 vapor recovery control program would be discontinued by 2015; therefore, ve hicle refueling emissions were assumed to have no additional controls beyond on-board canister vapor recove ry systems. The MOBILE6.2 model accounts for on-board vapor recovery canisters by default.

1.12 Example Emission Rates 

### Sample fleet average seasonal (winter, spring, summer, fall) and ozone season day emission factors produced by MOBILE6.2 on arterials at 30 mph are shown in Table 11. Refueling emission rates are shown in Table 12.

Table 11: Sample Arterial Emission Factors at 30 mph in grams per mile Year Pollutant Ozone Day Winter Spring Summer Fall 2002 CO 46.600 66.264 62.043 43.515 56.535 2002 VOC 4.864 4. 851 5.130 4.290 4.684 2002 NOX 5.689 6. 624 6.228 5.682 6.108

2015 CO 14.427 27.915 25.861 15.639 22.985 2015 VOC 1.680 1. 559 1.810 1.536 1.612 2015 NOX 1.780 2. 088 1.916 1.729 1.870Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### Table 12: Refueling Emission Factors in grams per mile Year Pollutant Ozone Day Winter Spring Summer Fall 2015 VOC 0.047 0. 056 0.047 0.038 0.043

1.13 Emissions Estimates 

### The emission rates in grams per mile calculate d with M6.2 were multipli ed by the temporally adjusted ADVMT estimates to calculate individual pollutant emissions for each of eight vehicle types and five road classes. Vehicle refueling emissions were calculated for the entire fleet.

Table 13: Vehicle Refueling Emissions, 2015 T/yr lbs/day 163 813



### Table 14: Onroad Mobile Emissions in Pounds per Ozone Season Day, 2002

Pollutant Class LDGV LDGT12 LDGT34 MC HDGV LDDV LDDT HDDV total Arterial 96,957 71,561 31,198 750 9,449 25 37 2,501 212,431 Interstate 61,862 44,65 1 19,533 469 5,645 14 20 1,367 133,533 Intrazonal 515 363 164 6 95 0 0 25 1,167 Local 14,597 10,517 4,672 149 2,093 4 6 552 32,580 Ramp 9,030 5,938 2,476 45 544 2 2 147 18,182 CO

total 182,960 133,030 58,04 4 1,420 17,826 45 66 4,592 397,893 Arterial 10,359 6,482 2,802 178 773 13 22 531 21,158 Interstate 5,935 3,675 1,572 101 411 7 12 263 11,974 Intrazonal 67 41 18 1 7 0 0 5 139 Local 1,754 1,088 470 28 161 2 4 106 3,614 Ramp 701 443 191 11 47 1 1 32 1,428 VOC

total 18,816 11,729 5,052 320 1,398 23 40 937 38,313 Arterial 7,262 4,696 2, 078 60 1,888 21 30 10,809 26,860 Interstate 4,131 2,689 1,185 38 1,142 14 20 8,556 17,788 Intrazonal 40 25 11 0 7 0 0 58 144 Local 1,127 718 318 8 244 3 5 1,636 4,061 Ramp 516 349 151 4 119 1 2 533 1,676 NOx

total 13,077 8,477 3, 743 110 3,400 39 57 21,592 50,528Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### Table 15: Onroad Mobile Emissions in Tons per Year, 2002

Pollutant Class LDGV LDGT12 LDGT34 MC HDGV LDDV LDDT HDDV total Arterial 19,561 15,694 6,523 110 1,478 4 6 433 43,803 Interstate 11,886 9,384 3,930 67 864 2 3 232 26,365 Intrazonal 102 81 34 1 15 0 0 4 237 Local 2,930 2,326 980 21 327 1 1 96 6,681 Ramp 1,704 1,280 515 7 83 0 0 25 3,614 CO

total 36,183 28,764 11,983 206 2,766 8 11 789 80,700 Arterial 1,693 1,101 471 22 106 2 4 92 3,490 Interstate 952 610 258 12 54 1 2 45 1,934 Intrazonal 11 7 3 0 1 0 0 1 23 Local 283 184 79 4 24 0 1 18 592 Ramp 114 75 32 1 6 0 0 6 234 VOC

total 3,052 1,977 843 39 191 4 7 161 6,273 Arterial 1,443 902 405 13 335 4 5 1,872 4,982 Interstate 810 507 227 8 199 2 3 1,454 3,212 Intrazonal 8 5 2 0 1 0 0 10 26 Local 218 137 61 2 43 1 1 283 746 Ramp 103 66 29 1 21 0 0 90 310 NOx

total 2,582 1,616 724 24 600 7 10 3,709 9,275



### Table 16: Onroad Mobile Emissions in Pounds per Ozone Season Day, 2015

Pollutant Class LDGV LDGT12 LDGT34 MC HDGV LDDV LDDT HDDV total Arterial 37,831 26,496 16,29 7 1,058 2,296 4 14 728 84,723 Interstate 24,614 17,007 10,458 685 1,389 2 8 388 54,550 Intrazonal 60 41 25 3 7 0 0 2 139 Local 5,941 4,132 2,534 230 551 1 3 177 13,569 Ramp 2,923 1,882 1,138 64 133 0 1 44 6,185 CO

total 71,368 49,559 30,452 2,039 4,377 7 26 1,339 159,166 Arterial 4,234 2,517 1,512 244 231 1 8 270 9,015 Interstate 2,258 1,371 815 136 116 0 4 122 4,823 Intrazonal 8 5 3 0 1 0 0 1 18 Local 757 437 268 41 46 0 2 60 1,612 Ramp 263 154 94 15 14 0 1 17 556 VOC

total 7,521 4,484 2,692 436 408 1 14 470 16,024 Arterial 2,747 2,058 1,609 96 400 1 11 3,485 10,408 Interstate 1,619 1,223 938 61 243 1 8 2,681 6,775 Intrazonal 5 3 3 0 0 0 0 5 17 Local 466 337 261 12 52 0 2 536 1,667 Ramp 172 130 104 6 23 0 1 179 614 NOx

total 5,009 3,751 2,915 176 719 3 22 6,887 19,482Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### Table 17: Onroad Mobile Emissions in Tons per Year, 2015

Pollutant Class LDGV LDGT12 LDGT34 MC HDGV LDDV LDDT HDDV total Arterial 10,385 7,258 4,281 155 440 1 2 127 22,651 Interstate 6,332 4,398 2,610 97 261 0 1 66 13,766 Intrazonal 16 11 6 0 1 0 0 0 35 Local 1,604 1,115 659 33 106 0 0 31 3,548 Ramp 732 488 286 9 25 0 0 8 1,547 CO

total 19,068 13,270 7,843 294 833 1 4 232 41,547 Arterial 681 425 264 29 32 0 1 47 1,479 Interstate 360 229 141 16 16 0 1 21 783 Intrazonal 1 1 1 0 0 0 0 0 3 Local 120 74 47 5 7 0 0 10 263 Ramp 42 25 16 2 2 0 0 3 90 VOC

total 1,204 754 468 51 56 0 2 81 2,617 Arterial 499 394 309 21 71 0 2 611 1,907 Interstate 293 230 177 13 42 0 1 460 1,218 Intrazonal 1 1 0 0 0 0 0 1 3 Local 82 64 50 3 9 0 0 94 302 Ramp 32 24 20 1 4 0 0 31 112 NOx

total 906 713 556 38 126 0 4 1,197 3,541

1 Email from Mark Harrington, Southwest Regi onal Transportation Council to Sally Otterson,

Washington State Department of Ecology. ADVMT estimates for 2000. June 6, 2003.

2 

### ADVMT estimates for 2015 from Mark Harr ington, Southwest Regional Transportation Council. Database date August 20, 2003.

3 Hertzog, Barbara and Borden, Hank. Adjustment Factors for Vehicle Miles Traveled . Washington State Department of Transportation. July 1992.

4 Annual Traffic Report . Washington State Department of Transportation. Pages XVI - XX (monthly traffic count data). 1994 data report.

5 MOBILE6.2 . US Environmental Protection Agency. Model executable file dated September 24, 2003.

6 Department of Licensing electronic data. Database snapshot July 2002.

7 

### National Transit Database Data Tables. Tables titled Age Distribution of Active Revenue Vehicle Inventory: Details by Trans it Agency Directly Operated Service . Federal Transit Administration. Data tables for 2002 and 2003. http://www.ntdprogram.com/NTD/ntdhome.nsf/ Docs/NTDPublicati ons?OpenDocument#

8 

### Spreadsheet schoolbuses2001.xls . Registration data provided by the Puget Sound Clean Air

Agency.

9 

### Spreadsheet schoolbuses2004.xls (originally titled Buses for DOE 24Aug04.xls ). Transmitted from Allan J. Jones, Director of Pupil Trans portation and Traffic Safety Education, Office of Superintendent of Public Inst ruction to Michael Boyer, WA Department of Ecology on Sept. 28, 2004.Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 10 

### Hellman, Karl H. and Heavenrich, Robert M. Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through 2004 . Advanced Technology Division, Office of Transportation and Air Quality, U.S. Envir onmental Protection Agency. EPA420-R-04-001. April 2004.

11 

### Climatological Data, Washington. January - December 2002 . Volume 106, Numbers 01 - 12. ISSN 0364-5320. National Oceanic and At mospheric Administration. National Environmental Satellite, Data and Informati on Service. National Climatic Data Center, Asheville, NC.

12 

### Temperature Determination . Guidance distributed at the MOBILE4.1 Workshop, EPA Region X, November 1991.

13 

### Procedures for Emission Inventory Prepara tion, Volume IV: Mobile Sources. EPA-450/4-81- 026d (Revised). 1992. Secti on 3.3.5 Correction Factors.

14 

### Supplement to the State Impl ementation Plan for Ozone (O3) in Vancouver, WA. Redesignation Request for Portland/Vancouver as Attainment for Ozone . Southwest Air Pollution Control Authority (now Southw est Clean Air Agency). March 19, 1996.

15 Western Climatic Data Center, Western US Climate Historical Summaries, Local Climate Data Summaries (June 20, 1997).

16 

### Spreadsheet Rel_hum1.xls . U.S. Environmental Protection Agency. Spreadsheet dated Jan 16, 2002.

17 

### 40 CFR 80.27.

18 

### Procedures for Emission Inventory Preparatio n, Volume IV: Mobile Sources. EPA-450/4-81- 026d (Revised) . 1992. Section 3.3.3 RVP Determination.

19 

### John Raymond, during 1990 base year St ate Implementation Plan efforts.

20 

### Memo from Philip Heirigs and Joe Roeschen, Sierra Research to Alison Pollack, ENVIRON International Corporation. Subject: Development of Calendar Ye ar 2002 County-Level Fuel Specification Data for the WRAP Modeling Domain . Dec. 14, 2004.

21 

### Spreadsheet of seasonal fuel RV P, sulfur and oxygen levels titled WRAP_Fuel_2002_toEnviron_121404.xls . Sierra Research.

22 IM Compliance Rate . Audit of Vehicles with July 1998 Expi ration Date. Department of Ecology Air Quality Program. Aug. 4, 1999.

23 1999/2000 Emission Test Data for Washington St ate - (Puget Sound, Spokane, Vancouver) - GVW < 8501 . Washington State Department of Ecology. March 20, 2002.

24 personal conversations with John Raymond, Department of Ecology.

25 User's Guide to MOBILE6.0 Mobile Source Emission Factor Model . United States Environmental Protection Agency. Air and Radiation. EPA420-R-02-001. January 2002.

26 

### May also generate factors for Interstates and Ramps combined.Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

## 2 Nonroad Mobile Sources, Excl uding Ships, Locomotives, and Aircraft Nonroad sources include gasoline, diesel, compressed natural gas (CNG) and liquefied petroleum gas (LPG) fueled equipment. EPA' s NONROAD2004 model was used to estimate emissions. 27 

### The model estimates emi ssions for 11 categories:

Agricultural Industrial Logging Airport Lawn/Garden (Co mmercial) Pleasure Craft Commercial Lawn/Garden (Residential) Railroad Construction/Mining Recreational

2.1 Activity Level, Emission Rates, and Temporal Allocation 

### The NONROAD2004 model was used to calcula te emissions for Clark County. The NONROAD2004 model can estimate emissions for USA counties for the years 1970 through 2050. Baseline equipment characteristics in the NONROAD2004 model are based on 1996-2000 data. To estimate future year projections, th e model includes growth and scrappage rates for equipment in addition to a variety of contro l program options. The model can calculate emissions for each of the four seasons. Emission s for the period selected are estimated either for the total period or for a typical day (weekday or weekend) in that peri od. For this inventory, annual emissions were calculated by summing peri od emissions for each of the four seasons. Daily emissions were calculated as summer weekday emissions.

In addition to the county and time peri od, NONROAD2004 requires seasonal information on minimum, maximum and ambient temperatures. Am bient temperature is defined as: {min + [2/3 x (max-min)]}. 13 

### The model also requires fuel RVP, sulfur content, and fuel control programs. The meteorological and RVP parameter values are shown in Table 8 (see Onroad Mobile Sources above).

Diesel fuel sulfur values content came from th e NONROAD2004 diesel sulfur file (sulfur.txt). Values were available for the years 2000 – 2040. Gasoline sulfur c ontent for 2002 came from the onroad model MOBILE6.2 and was 279 ppm. Gaso line sulfur for 2015 is the legal limit of 30 ppm. The NONROAD2004 model default template sulfur value of 30 ppm was used for CNG/LPG. To be conservative, no stage 2 control was assumed. Fuel sulfur values are shown in Table 18.

Table 18: NONROAD2004 Fuel Sulfur Parameters

Fuel 2002 Sulfur % 2015 Sulfur % Gasoline 0.0279 0.0030 Diesel 0.2283 0.0011 LPG/CNG 0.003 0.003

2.2 Emissions 

### Annual and ozone season day emissions are shown be low. Annual emissions are in tons per yearPrepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### and seasonal emissions are in pounds per day.

Table 19: Nonroad Emissions, 2002
Tons per year Pounds per weekday CLASSIFICATION VOC CO NOx VOC CO NOx Agricultural 7 59 50 90 771 636 Airport 0 0 0 0 3 2 Commercial 171 4,398 128 1,108 29,881 760 Construction/Mining 191 1, 584 1,050 2,081 17,944 11,455 Industrial 104 1,646 431 785 12,763 3,207 Lawn/Garden (Commercial) 615 9,012 101 6,196 111,049 1,058 Lawn/Garden (Residential) 306 4,941 33 2,394 43,173 219 Logging 29 186 46 183 1,232 290 Pleasure Craft 128 312 10 801 1,654 49 Railroad 1 11 4 6 81 26 Recreational 199 1,143 9 1,477 8,926 56 TOTAL 1,751 23,292 1,862 15,122 227,476 17,760Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 

### Table 20: Nonroad Emissions, 2015
Tons per year Pounds per weekday CLASSIFICATION VOC CO NOx VOC CO NOx Agricultural 4 47 35 48 622 440 Airport 0 0 0 0 2 1 Commercial 122 6263 109 821 42,618 648 Construction/Mining 97 1300 577 1,061 14,856 6,296 Industrial 16 348 117 116 2,679 852 Lawn/Garden (Commercial) 366 11136 86 3,455 137,770 909 Lawn/Garden (Residential) 187 6419 29 1,481 56,342 191 Logging 19 246 12 118 1,646 77 Pleasure Craft 73 312 14 526 1,648 68 Railroad 1 12 3 5 85 21 Recreational 192 1641 11 1,449 12,781 70 TOTAL 1,076 27,725 994 9, 080 271,049 9,571Prepared by Washington DOE’s Sally Otterson, May 31, 2006 sw03maint_rev 27 

### NONROAD2004, version 2.3c . April 2004.

13 

### Procedures for Emission Inventory Prepara tion, Volume IV: Mobile Sources. EPA-450/4-81- 026d (Revised). 1992. Secti on 3.3.5 Correction Factors