# Portneuf Valley PM 10 

# Maintenance Plan

Amendment

Transition from MOBILE6 Model to MOVES Model
and to Revise Road Dust Methodology

State of Idaho Department of Environmental Quality

April 201 4Printed on recycled paper, DEQ

, April 201 4

, PID
PVAB

, CA 61068 . Costs associated with this publication are available from the State of Idaho Department of Environmental Quality in accordance
with Section 60

- 202, Idaho Code.

# Portneuf Valley PM 10 

# Maintenance Plan
Amendment

Transition from MOBILE6 Model to MOVES Model
and to Revise Road Dust Methodology

April 201 4

Prepared by Idaho Department of Environmental Quality

Pocatello Regional Office 444 Hospital Way, #300
Pocatello

, Idaho 83201This page intentionally left blank for correct double

- sided printing.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

iii 

### Table of Contents

Acronyms, Abbreviations, and Symbols

................................ ................................ ........................ v

Introduction

................................ ................................ ................................ ................................ ..... 1
Background

................................ ................................ ................................ ................................ ..... 1

Emission Calculations

................................ ................................ ................................ ..................... 2
Description of Modeling Used

................................ ................................ ................................ ........ 2
Planning Assumptions

................................ ................................ ................................ .................... 3
Existing MVEB

................................ ................................ ................................ ............................... 3
Input Data

................................ ................................ ................................ ................................ ........ 4
Budgets and Safety Margins

................................ ................................ ................................ ........... 4

Revised MVEB for the Period 2011

– 2020

................................ ................................ ..................... 5
Emission Inventory Growth and Control Assumptions Unchanged

................................ ............... 6

Conclusion

................................ ................................ ................................ ................................ ...... 6

References

................................ ................................ ................................ ................................ ....... 7
Appendix A. Development of the Year 2011 and Year 2020 Mobile Source Emissions Inventories and Conformity Test for the Portneuf Valley Nonattainment Area, Idaho
Appendix B. Procedure for Revising MVEBs for PVNAA to Reflect MOVES and Paved Road Dust Model Changes
Appendix C. 2004 SIP Emission Inventory with Updated On

- road Mobile Emissions
Appendix D. Public Involvement



### List of Tables

Table 1. Existing MVEB established in 2004 PVNAA SIP.

................................ .......................... 3 Table 2. Comparison of 2013 on

- road emissions with existing 2004 MVEBs in terms of net

PM 10 , including primary and secondary particulate, assuming 100% NO

x conversion.

.. 5 Table 3. Revised motor vehicle emission budgets for the PVNAA.

................................ .............. 6Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

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v 

## Acronyms

, Abbreviations , and Symbols

ATR a utomatic t raffic r ecorder

AP

- 42 Compilation of Air Pollutant Emission Factors

BTPO Bannock Transportation Planning Organization

EPA United States Environmental Protection Agency

FR Federal Register

DEQ Idaho Departmen t of Environmental Quality

ITD Idaho Transportation Department

MOBILE6 Vehicle E mission s M odeling S oftware

MOVES Motor V ehicle E mission S imulator

MVEB m otor v ehicle e missions b udget

NAAQS National Ambient Air Quality Standards

NEI National Emission Inve ntory

NH 4 NO 3 ammonium nitrate

NO

x n itrogen o xides

PM 2.5 p articulate m atter under 2.5 microns in size

PM 10 p articulate m atter under 10 microns in size

PVNAA Portneuf Valley Nonattainment Area

SIP State Implementation Plan

TDM Travel Demand Model

TIP T ransportation I mprovement P rogram

TPY t ons per y ear

VOC v olatile o rganic c ompoundsPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

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1 

## Introduction

The purpose of th is amendment is to revise the Portneuf Valley PM 10 Nonattainment Area S tate
I mplementation P lan , Maintenance Plan, and Redesignation Request (DEQ 2004) motor vehicle emissions budget (MVEB) by incorporating e mission estimates made with the Motor Vehicle Emission Simulator (MOVES), the latest United States Environmental Protection Agency ( EPA )

- required motor vehicle emissions factor model (EPA 20 09, 2011a) and with an updated
road dust estimation method (EPA 2011 b )

. The revisions in this amendment only change emission related to the MVEB and no changes are made to the point or area source emissions.

Currently, the area’s existing MVEB is based on the MOBILE 5 model, the predecessor to the
MOVES mod el and an old ( 1995 ) r oad d ust estimation method (EPA 1995 )

. T his amendment update s the MVEB submitted with the original S tate I mplementation P lan ( SIP ) , approved by EPA in July 2006, using the se latest EPA

- approved methods

, which are now required for
conf ormity demonstrations. No change in activity or control measures is included; this is simply a change to the latest EPA

- mandated road dust and on

- road mobile emissions method s /model, and the most current planning assumptions. The updated MVEB is demonstrat ed to be equivalent
to the MVEB in the 2004 SIP in terms of particulate matter under 10 microns in size ( PM 10 )
contribution to the airshed.



## Background

In areas that are not meeting the National Ambient Air Quality Standards (NAAQS), the Clean Air Act requi res the state to develop a SIP contain ing emission control measures to reduce emissions enough to return the area to compliance with NAAQS. As part of developing control

measures , a MVEB is developed that sets emission limits for all current and future transportation projects. Once the MVEB is established in the SIP, Metropolitan Planning Organizations
estimate the regional vehicle emissions from all the local proposed road projects in the Transportation I mprovement Program (TIP) and compare those emissions with the SIP’s MVEB. This process is known as transportation c onformity

.

In March 201 3 , MOVES replaced MOBILE6 as EPA’s official motor vehicle emissions factor

model required for all regional emission a nalysis in support of transportation conformity

. The Bannock Transportation Planning Organization (BTPO) addresses the MVEB for the Portneuf Valley a ttainment a rea.

In general

, the MOVES model calculates higher nitrogen oxides ( NO

x ) and particulate matter
under 2.5 microns in size ( PM 2.5 ) emissions than the previous MOBILE6 model when the activity levels are held constant . Because of the higher emissions estimates resulting from MOVES, it is difficult to show conformity with SIPs that contain MVEB develope d using

MOBILE6

, even when there has been no increase in actual emissions.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

2 

## Emission Calculations

EPA approved the Portneuf Valley PM 10 maintenance plan and designated the area in attainment

o n July 13, 2006 (71 FR 39574)

. This approved plan established MVEBs for on

- road sources. DEQ has updated the existing MVEBs in the PM 10 m aintenance plan for the P ortneuf Valley using the newer EPA

- approved emissions model (MOVES2010b) and the latest paved road dust
emission method as de tailed in AP

- 42

. This amendment to the SIP will revis e the MVEBs to
reflect both new methods now required by EPA.

In addition to the on

- road mobile emissions estimated by the MOBILE6 /MOVES models, paved
road dust PM 10 emissions are included in the MVEB. T he 2004 SIP attainment demonstration
used to establish the existing MVEB included paved road dust estimates made using EPA’s 1996

AP

- 42 emission estimation guidance and incorporated locally determined road silt loading information developed in a 1996/1997 study by Light (1 998 ).

In January 2011

, EPA revised its AP

- 42 paved road dust estimation method (EPA 2011 b )

, and DEQ used the new estimation guidance to update estimate s of paved road dust emissions. A survey of the Pocatello and Chubbuck city road departments indicated that major changes in the
use of wintertime antiskid treatments occurred between 199 7 and 2012, including higher salt

- to

sand ratios in the antiskid treatments, pre storm brine application to reduce the amount of
antiskid materials re quired, and a greater number of sweepers to clean up the antiskid materials
that are used (Appendix A). Based on this survey

, silt loadings based on traffic volume were used as recommended by EPA (EPA 2011 b ) to account for wintertime antiskid treatment rat her than the silt loading measured in the area 15 years earlier . As a result of the reduced sand usage and the updated emission estimation methods, a significant reduction in paved road dust is
estimated for years 2011 and 2020. The paved road dust reducti ons are greater than the increase

in direct exhaust PM 10 and secondary PM 10 due to precursor NO

x that occurred when MOVES replaced MOBILE6 . T he net effect is a reduced on

- road mobile emissions inventory.



## Description of Modeling Used

On March 2, 2010, EPA released a new mobile source emissions model called the Motor Vehicles Emissions Simulator 2010 (MOVES2010 ) . The EPA provided a 2

- year grace period to transportation planning organizations, ending March 2, 2012, during which the older MOBILE6
emissions could still be used to model emissions for transportation projects to meet the requirements of transportation conformity (75 FR 9411).

On October 13, 2011, EPA proposed a 1

- year extension to the 2

- year grace period because states
and localities needed more time to transition to using MOVES2010a and to develop the technical capacity to use MOVES2010a (76 FR 63575). EPA finalized the extension on February 27, 2012 (77 FR 11394). The 1

- year extension provides additional time that may be critical fo r nonattainment and maintenance areas to learn and apply MOVES2010a for regional conformity analyses. Any new transportation conformity analysis started after March 2, 2013, must use the
MOVES model.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

3 The EPA issued the MOVES2010b version of the model and i ts associated guidance in April 2012

, and it is the version in effect throughout the period of this SIP r evision analysis and is the version used by DEQ

.



## Planning Assumptions

To operate the MOVES model at the county

- level as required by EPA for SIP

- level e mission
inventories

, DEQ develop ed an input database for each specific combination of inputs. This
section discusses the assumptions, sources of input information, and calculation methodologies involved in developing SIP

- level MOVES input databases.

In Nov ember 2012, DEQ completed statewide on

- road emission estimates in support of the 2011 National Emission Inventory (NEI). This comprehensive project (DEQ 2012) gathered detailed information from the statewide motor vehicle registration database to describe the motor vehicle source population (ITD 2012a) and traffic counts by vehicle length from every permanent

a utomatic t raffic r ecorder (ATR) in the state (ITD 2012b). In addition

, tele phone and e

- mail surveys filled in the bus and refuse truck source populat ion data that may be unreliable in the registration database and in the national defaults. In view of this SIP

- level detail in the NEI MOVES inputs, the Bannock County source population and temporal profiles developed for the NEI were used along with BTPO’ s T ravel D emand M odel (TDM) for the Portneuf Valley

N onattainment A rea ( PVNAA ) (Parsons 2012) to develop local inputs for the Portneuf Valley

. The use of the Bannock County inputs from the NEI statewide database, which was extensively quality assured and found to be consistent with other counties in Idaho of similar population

en sures that the P ortneuf Valley results are robust and internally c onsistent with the rest of Idaho.



## Existing MVEB

The 2004 PVNAA SIP established MVEB for 2005, 2010

, and 2020 (DEQ 2004). The existing MVEBs were developed consistent with the emission s inventory and attainment demonstration that showed future compliance wi th NAAQS for PM 10 . The existing MVEBs established in the
2003 SIP are shown in Table 1

.

Table 1

. Existing MVEB established in 2004 PVNAA SIP

.
Year PM 10 (TPY) NO
x (TPY) VOC (TPY)

2005 897 1,575 983

2010 1,120 1,085 716

2020 1,364 514 585

Notes : motor vehicle emission budget (MVEB); Portneuf Valley N onattainment A rea (PVNAA); S tate I mplementation P lan (SIP); particulate matter with a diameter less than 10 microns (PM 10 ); tons per year (TPY); nitrogen oxides (NO x ); volatile organic compound (VOC)

The existing budgets include on

- road mobile emissions computed using MOBILE6 , paved road dust emissions computed u sing the 1995 version of the AP

- 42 p aved r oad d ust emission factor methodology that incorporated locally determined silt loading factors , and a small amount ofPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

4 unpaved road dust emissions from the few remaining unpaved roads in the area. No significant

unp aved roads remain in the PVNAA in 2013.



## Input Data

The on

- road mobile emission inventory for the PVNAA was updated for 2011 and 2020 as
described in Appendix A (DEQ 2013). Emissions estimates for 2010 were not made because ( a) 2010 had passed and conformit y for 2010 and prior years was already completed using

MOBILE6 , and ( b) newer information was available for 2011 as a result of the 2011 NEI project. DEQ used SIP

- quality, county

- level MOVES inputs for the 2011 NEI so that it would be adequate for SIP documentation purposes. E arly in 2013

, DEQ updated the 2011 NEI inputs to reflect activity data from the P ortneuf Valley TDM developed by B T PO. As a result

, the more recent 2011 emissions will be used to replace the existing 2010 MVEBs since 2010 is no longer
of interest and the recent model year is more relevant and timely. The SIP

- level MOVES inputs developed for the 2011 NEI include source popu lation data from the Idaho Department of Motor Vehicles, traffic temporal information from permanent ATRs, and bus and refuse truck local survey information (DEQ 2013).



## Budgets and Safety Margins

The following demonstrates that the revised MVEB resulting from EPA

- mandated changes in the

on

- road and paved road dust emission models results in lower net PM 10 in the airshed.

It should be noted that actual on

- road activity levels are not changing significantly beyond normal growth

, and this demonstration refle cts only changes in the estimated AP

- 42 road dust

e missions and i n the on

- road mobile modeling emission estimates. This section and Appendix B describe how DEQ calculate d the overall net effect of th ese emission calculation changes for
total PM 10

.

The net effective PM 10 contribution is the combination of direct PM 10 emissions plus the NO

x that has been converted to the secondary aerosol composed of ammonium nitrate (NH 4 NO 3 )

. Since the actual conversion rate of NO

x to NH 4 NO 3 cannot be estimated without diff icult and
time

- consuming photochemical modeling, DEQ followed the most conservative possible approach and estimate d 100% conversion. Since VOC s only act similar to a catalyst in facilitating the NH 4 NO 3 formation chemistry and do n o t directly form new PM 10 separate from
the nitrate formation , they are not included in calculating the net effective PM 10 contribution to
the airshed (Appendix B)

. Table 2 shows the compariso n of total PM 10 (direct PM 10 + 100%
conversion of NO

x to NH 4 NO 3 ) using the existing MVEB in the 2004 SIP and a MVEB developed in 2013 with MOVES and the new AP

- 42 road dust calculations. The 2013 estimates show an increase in secondary particulate formation and a decrease in direct PM 10 , but the total

PM 10 still remains below th at in the existing 2010 and 2020 MVEB s from the SIP

, which demonstrated compliance with the PM 10 NAAQS.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

5 Table 2

. Comparison of 2013 o n
- road e missions with existing 2004 MVEBs in terms of net PM 10 , including primary and secondary particulate, assuming 100% NO
x conversion.

Existing SIP MVEB
with 100% NO
x Conversion Rate 2013 Estimates with
100% NO
x Conversion Rate Difference, Existing
SIP MVEB

— 2013
Estimates

Year 2010 2011 2010/2011

Secondary PM 10 produced
from NO
x and VOC 2,745 3,347

- 602

Primary PM 10 1,120 382 738

Total PM 10 3,865 3,729 136

Year 2020 2020 2020

Secondary PM 10 produced from NO
x and VOC 1,300 1,647

- 347

Primary PM 10 1,364 379 986

Total PM 10 2,664 2,026 639

Notes : motor vehicle emission budget ( MVEB); particulate matter with a diameter less than 10 microns (PM 10 ) ; nitrogen oxides (NO x ); State Implementation Plan (SIP); volatile organic compound (VOC)

I f the updated emissions estimates are used directly as MVEB s , then minor model input differences in future conformity tests could potentially cause the TIP emissions estimates to exceed the updated budgets. To avoid this potential problem, safety factors are typically built
into the MVEBs to the extent that can be tolerated while still demonstrating future year NAAQS compliance in the attainment demonstration, or in this case, while still showing equivalence with the existing MVEB.

It was determined a safety margin of 3 .1% could be added to revised 2011 MVEBs and 3 1.5%
could be added to the revised 2020 MVEBs without exceeding the total PM 10 in the e xisting

MVEB s

. Since the existing SIP MVEB is consistent with an overall emission inventory and the approved attainment demonstration model showing future year complianc e with the NAAQS (DEQ 2004), the revised model change MVEBs will remain consistent with the attainment demonstration as long as long as they are equivalent to the existing MVEBs in terms of the net

PM 10 qua nt ity added to the airshed.



## Revised MVEB for the P eriod 2011

– 2020

The analysis above demonstrates that model changes resulting from the use of the MOVEs2010b
model and the 2011 AP

- 42 p aved r oad d ust method results in new MVEBs that are equivalent to the existing (2004 SIP) MVEBs in terms of PM 10 contributions to the PVNAA airshed.

The resulting revised MVEB for this period is shown in Table 3 . Conformity tests for any TIPs
conducted from the a pproval of the MVEBs in this EIP revision through 2019 will be required to meet the budget shown for 2011 . This is a conservative budget because, as noted in Appendix B,
the 2011 MVEB includes the maximum (2011) MOVES direct PM 10 emissions plus the
maximum (2020) paved road dust emissions for the period

. Any TIP conducted in 2020 and beyond will be required to meet the budget shown for 2020.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

6 Table 3

. Revised m otor v ehicle e mission b udgets for the PVNAA

.
Year PM 10 (TPY) NO
x (TPY) VOC (TPY)

2005 N/A N/A N/A

2011 415 1

, 364 903

2020 498 856 651

Notes : Portneuf Valley N onattainment A rea (PVNAA); particulate matter with a diameter less than 10 microns (PM 10 ) ; tons per year (TPY); nitrogen oxides (NO x ); volatile organic compound (VOC) ; not applicable (N/A)



## Emission Inventory G rowth and C ontrol A ssumptions
U nchanged

This report demonstrates that MVEBs updated using MOVES and the 2011 r oad d ust methodology are equivalent to the existing MVEBs in the 2004 SIP. Th e other portions of the
emissions inventory are unchanged by this modification

, and the growth and control strategy assumptions used in the 2004 SIP are still valid. The emission s inventory developed for the 2004 SIP is reproduced in Appendix C, with the new MVEBs provided for co mparison.

Control strategy assumptions for source categories other than on

- road vehicle are not changed as part of this revision and are unchanged since the SIP was published in 2004 . In addition, the growth assumptions used in the 2004 SIP to project emi ssions for the future years are still valid.
The 2004 SIP analysis used the population growth from 1990 to 2000 (1.4% per year) to forecast population and household growth to the future year attainment dates , including 2010 and 2020,
for generally all the anthropogenic area source categories

. (Agriculture and stationary sources were assumed to remain level.) Subsequent census data indicate that combined population growth for Chubb u ck and Pocatello , the population centers of the PVNAA

, actually averaged

1.2 % per year between 2000 and 2010, and is estimated to average only 0.6% for each city in 2011 and 2012 (US Census 2013). This is lower tha n the growth rates assumed in the SIP to occur for every year after 2000. The cities of Chubb u ck and Pocatello represe nt nearly the entire populated portion of the PVNAA, so it is clear that growth assumptions used in the 2004 SIP are
still valid.



## Conclusion

The revised MVEB included in Table 3 will apply to future transportation conformity
determination s . With these proposed changes to the MVEB, the SIP will continue to s how
maintenance of the 24

- hour PM 10 standard because it is equivalent to the MVEB used in the
2004 attainment dem onstration. Th is SIP amendment will lead to an equitable and more relevant result when evaluating transportation impacts on the area’s air quality.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

7 

## References

DEQ (Idaho Department of Environmental Quality) . 2004. Portneuf Valley PM 10 Nonattainment Area State Implementation Plan, Maintenance Plan and Redesignation Request

. Pocatello

, ID: DEQ.

DEQ (Idaho Department of Environmental Quality)

. 2012

. Development of the 2011 Paved Road Dust Inventory for the National Emission Inventory

. Boi se , ID: DEQ.

DEQ (Idaho Department of Environmental Quality). 2013. Development of the Year 2011 and Year 2020 Mobile Source Emissions Inventories for the Portneuf Valley Non

- Attainment Area, Idaho

. Boise, ID: DEQ

.

EPA (United States Environmental Protect ion Agency). 1995

. “ Paved Road Dust .” Section

13.2.1

. Compilation of Air Pollutant Emission Factors

. Washington, DC: Office of Air Quality Planning and Standards

.
EPA (United States Environmental Protection Agency). 2009. Motor Vehicle Emission
Simulator (MOVES) 2010: User Guide

. Assessment and Standards Division, Office of Transportation and Air Quality, EPA

- 420

- B

- 09

- 041. December 2009.

EPA (United States Environmental Protection Agency) . 2011 a

. MOVES (Motor Vehicle Emission Simulator)

. http://www.epa.gov/otaq/models/moves/index.htm

.

EPA (United States Environmental Protection Agency). 2011 b

. “ Paved Road Dust .” Section
13.2.1

. Compilation of Air Pollutant Emission Factors

. Washington, DC: Of fice of Air Quality Planning and Standards

.

ITD (Idaho Transportation Department) . 2012a. Motor V ehicle R egistration D atabase

. Boise,

ID: ITD Department of Motor Vehicles.

ITD (Idaho Transportation Department) . 2012b. Automatic T raffic R ecorder D atabase ( S tatewide, R aw D ata)

. Boise, ID: ITD Department of Motor Vehicles

.
Light , J . 1998. Pocatello Road Dust Study Final Report

. Prepared for Bannock Transportation Planning Organization

. Pocatello, I D

.

Parsons (Parsons Brinkerhoff, PB Americas, Inc.) . 2012. BTP O Travel Model User’s Guide

. Prepared for Bannock Transportation Planning Organization ( Pocatello, ID ) . Portland,

OR: Parsons.

US Census (United States Census Bureau). 2013. Annual Estimates of the Resident Population: April 1, 2010 to July 1, 2012

. Washington, DC: United States Department of Commerce.
Accessed December 2013. http://factfinder2.census.gov/bkmk/table/1.0/en/PEP/2012/PEPANNRES/0400000US1 6.1
6200Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

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- sided printing.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES



## Appendix A

. Development of the Year 2011 and Year 2020

Mobile Source Emissions Inventories and Conformity Test for the Portneuf Valley Nonattainment Area, IdahoPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

This page intentionally left blank for correct double

- sided printing.

# Development of the Year 2011 and Year 2020

Mobile Source Emissions Inventories and Conformity Test for the Portneuf Valley Nonattainment Area, Idaho

December 201 3

Prepared by
Idaho Department of Environmental Quality
Technical Services Division
1410 N. Hilton Boise, ID 83706This page intentionally left blank for correct double

- sided printing.iii 

### Table of Contents

Abbreviations, Acronyms, and Symbols

................................ ................................ ........................ v

1 Introduction

................................ ................................ ................................ .............................. 1

2 Methodology: MOVES Input Database Development

................................ ............................ 1

2.1 VMT

- Related Inputs

................................ ................................ ................................ ......... 4

2.1.1 Annual VMT

................................ ................................ ................................ ............. 4

2.1.2 Road Type

................................ ................................ ................................ ................. 5

2.1.3 Monthly, Daily, and Hourly VMT

................................ ................................ ............ 5

2.2 Source

- Related Inputs

................................ ................................ ................................ ...... 6

2.2.1 Source Type Population

................................ ................................ ............................ 6

2.2.2 Age Distribution

................................ ................................ ................................ ........ 7

2.3 VHT

- Related Inputs

................................ ................................ ................................ ......... 7

2.3.1 Ramp Fractions

................................ ................................ ................................ ......... 8

2.3.2 Average Speed Distribution

................................ ................................ ...................... 8

2.4 Fuel

- Related Inputs

................................ ................................ ................................ .......... 9

2.4.1 Fuel Supply

................................ ................................ ................................ ............... 9

2.4.2 Fuel Formulation

................................ ................................ ................................ ..... 10

2.4.3 Alternative Vehicle Fuels and Technology

................................ ............................. 10

2.5 Meteorology

................................ ................................ ................................ ................... 10

2.6 Inspection and Maintenance Programs

................................ ................................ ........... 10

2.7 On

- Road Retrofits

................................ ................................ ................................ .......... 11

3 Methodology: Paved Road Dust

................................ ................................ ............................ 11

3.1 Vehicle Miles Traveled

................................ ................................ ................................ .. 12

3.2 Road Dust Emission Factor

................................ ................................ ............................ 12

3.2.1 Particle Size Multipliers

................................ ................................ .......................... 13

3.2.2 Silt Loading

................................ ................................ ................................ ............. 13

3.2.3 Average Vehicle Weight by Roadway Type

................................ .......................... 14

3.2.4 Precipitation Data

................................ ................................ ................................ .... 15

4 Results

................................ ................................ ................................ ................................ .... 15

4.1 On

- Road Mobile Source Emission Estimates

................................ ................................ 15

4.2 Paved Road Dust Emission Estimates

................................ ................................ ............ 16

5 Quality Control and Quality Assurance

................................ ................................ ................. 16

References

................................ ................................ ................................ ................................ ..... 17
Appendix A. Crossw alk between BTPO TDM Road Types, FHWA Roadway Types, and MOVES Roadway Types

................................ ................................ ................................ .............. 19
Appendix B. Crosswalk between ATR Length Bins, FHW A Vehicle Classes, and MOVES Source Types

................................ ................................ ................................ ................................ . 20
Appendix C. ITD Statewide Vehicle Classification Data

................................ ............................. 21iv 

### List of Figures

Figure 1. Motor Vehicle Emission Simulator input files and groups.

................................ ............ 3



### List of Tables

Table 1. Idaho county groups for MOVES modeling purposes.

................................ ..................... 2
Table 2. MOVES road type descriptions.

................................ ................................ ....................... 4
Table 3. MOVES source type descriptions.

................................ ................................ .................... 4

Table 4. Travel Demand Model

- based annual vehicle miles traveled.

................................ ........... 5
Table 5. Crosswalk between MOVES source types and data sources for source

- related MOVES input parameters.

................................ ................................ ................................ .. 6
Table 6. MOVES speed bins.

................................ ................................ ................................ .......... 8
Table 7. Roadway type definitions in road dust calculation.

................................ ........................ 12
Table 8. Silt loadings used for paved road emission factor calculation.

................................ ....... 14
Table 9. Antiskid impr ovements to lower silt loadings in Pocatello and Chubbuck.

................... 14
Table 10. Average vehicle weight by vehicle type.

................................ ................................ ...... 15
Table 11. Number of days with greater than 0.01 inches of precipitation for each month in

2011.

................................ ................................ ................................ ................................ .. 15

Table 12. Annual on

- road emissions in PVNAA.

................................ ................................ ......... 16
Table 13. Annual paved road dust emissions in PVNAA.

................................ ............................ 16



### List of Equations

Equation 1. Equation used to estimate vehicle population for source types without local data.

.... 7
Equation 2. Equation used to estimate vehicle population for 2020.

................................ .............. 7
Equation 3. Akcelik volume delay function.

................................ ................................ .................. 9
Equation 4. Paved road dust emission factor.

................................ ................................ ............... 1 2
Equation 5. VMT

- weighted silt loading.

................................ ................................ ...................... 13v



## Abbreviations, Acronyms, and Symbols

ADT average daily traffic

ATR automatic traffic recorder

AVFT alternative vehicle fu el s and technology

BTPO Bannock Transportation Planning Organization

CO carbon monoxide

DEQ Idaho Department of Environmental Quality

DMV Idaho Department of Motor Vehicles

E10 fuel blend of 10% ethanol and 90% gasoline

EPA U nited S tates Environmental Protection Agency

FHWA Federal Highway Administration

HPMS Highway Performance Monitoring System

I/M inspection and maintenance

ITD Idaho Transportation Department

MOVES Motor Vehicle Emissions Simulator

m ph miles per hour

MVEB motor vehicle emission budget

NEI National Emission Inventory

NH 3 ammonia

NO

x nitrogen oxides

PM 10 particulate matter with a diameter less than 10 microns

PM 2.5 particulate matter with a diameter less than 2.5 microns

PVNAA Portneuf Valley Nona ttainment Area

SIP S tate I mplementation P lan

SO 2 sulfur dioxide

TDM T ravel D emand M odel

TVRDS Treasure Valley R oad D ust S tudy

VHT vehicle hours traveled

VIN vehicle identification number

VMT vehicle miles traveled

VOC volatile organic compoundvi This page intentionally left blank for correct double

- sided printing.1



## 1 Introduction

On

- road mobile emission inventories for the Portneuf Valley Non a ttainment Area (PVNAA) are required for the State Implementation Plan (SIP) ten

- year update documentation and for future conformity determinations to be made by the Bannock Transportation Planning Organization (B T PO), the metropolitan planning organization for Bannock County

, Idaho. While current motor vehicle budgets established by the current SIP for particulate matter with a diameter less
than 10 microns ( PM 10 ) (DEQ 2004) were developed using the MOBILE motor vehicle emissions model, all future SIP documentation and conformity determinations after March 2,

2013

, must be developed using the Uni ted States Environmental Protection Agency’s ( EPA’s )

new Motor Vehicle Emission Simulator ( MOVES ) model. The purpose of the PVNAA on

- road emission inventory described in this report is to support the SIP m aintenance p lan ten

- year update and conformity dete rminations to be made after March 2, 2013. Conformity determinations made prior to March 2, 2013

, must be made using the same methodologies used to develop the m otor v ehicle e mission b udgets (MVEB) currently in effect as established in the

200 4 P ortneuf Valley PM 10 S tate I mplementation P lan, Maintenance Plan, and Redesignation Request (DEQ 2004 )

.
The Motor Vehicle Emissions Simulator (MOVES2010b) (EPA 201 1a ) is the current EPA

designated model for on

- road mobile e mission inventory development for SIP m aintenance p lans and for Federal Highway Administration (FHWA) transportation conformity determinations. The

on

- road mobile source emissions inventory was developed using MOVES 2010b according to EPA guidance Using MOV ES to Prepare Emission Inventories in State Implementation Plans and Transportation Conformity: Technical Guidance for MOVES2010, 2010a and 2010b (EPA 2012)

.
The paved road dust emissions were developed using the latest EPA

- recommended AP

- 42, Compilation of Air Pollutant Emission Factors method (EPA 2011 b ). There are no significant unpaved road s in the PVNAA , t hus unpaved road emission s were not estimated.

This report details the methodologies and results for the MOVES on

- road emissions modeling and paved road dust computations used to de velop the 2011 and 2020 on

- road emission inventories.



## 2 Methodology: MOVES Input Database Development

To operate the MOVES model at the county

- level as required by EPA for SIP

- level emission
inventories

, the Idaho Department of Environmental Quality ( DEQ ) develop ed an input database for each specific combination of inputs. This section discusses the assumptions, sources of input
information

, and calculation methodologies involved in developing SIP

- level MOVES input
databases.

In November 2012, DEQ completed statewide on

- road emission estimates in support of the 2011 National Emission Inventory (NEI) . This comprehensive project (DEQ 2012) gathered detailed information from the statewide motor vehicle registration database to describe the motor vehicle

source population and traffic counts by length from every permanent a utomatic t raffic r ecorder (ATR) in the stat e. In addition tele phone and e

- mail surveys filled in the bus and refuse truck source population data that may be unreliable in the registration databa se and in the national2

defaults. In view of this SIP

- level detail in the NEI MOVES inputs, the Bannock County source population and temporal profiles developed for the NEI were used along with B T PO’s T ravel

D emand M odel (TDM) (Parsons 2012) to develop loca l inputs for the PVNAA. The use of the Bannock County inputs from the NEI statewide database, which was extensively quality assured and found to be consistent with other counties in Idaho of similar population en sures that the
PVNAA results are robust and internally consistent with the rest of Idaho.

Based on similarity of geographic features, vehicle travel patterns, and data sources, DEQ grouped all 44 Idaho counties into three groups: North ern Idaho, South ern Idaho, and Treasure Valley to use the ATR dat a in developing the statewide 2011 NEI inputs ( Table 1 ). A m ajority of PVNAA resides in Bannock County and belongs to the s outh ern Idaho group. Because all of the
urban s outh ern Idaho group ATR sites except one reside in PVNAA and nearly all roads in PVNAA are urban roads, the s outh ern Idaho group ATR data represent PVNAA very well

.

Table 1

. Idaho c ounty g roups for MOVES modeling purposes

. County Group County

ID County

Name County

Group County ID County Name

North ern Idaho 16009 Benewah

South ern Idaho (continued) 16031 Cassia

16017 Bonner 16033 Clark

16021 Boundary 16037 Custer

16035 Clearwater 16039 Elmore

16049 Idaho 16041 Franklin

16055 Kootenai 16043 Fremont

16057 Latah 16045 Gem

16061 Lewis 16047 Gooding

16069 Nez Perce 16051 Jefferson

16079 Shoshone 16053 Jerome

Treasure Valley 16001 Ada 16059 Lemhi

16027 Canyon 16063 Lincoln

South ern Idaho 16003 Adams 16065 Madison

16005 Bannock 16067 Minidoka

16007 Bear Lake 16071 Oneida

16011 Bingham 16073 Owyhee

16013 Blaine 16075 Payette

16015 Boise 16077 Power

16019 Bonneville 16081 Teton

16023 Butte 16083 Twin Falls

16025 Camas 16085 Valley

16029 Caribou 16087 Washington

Note : Motor Vehicle Emission Simulator (MOVES)

T he required MOVES inputs, grouped by common data source

, are shown in Figure 1 . For example, VMT Related inputs such as road type distribution and monthly, daily

, and hourly traffic profiles (top box) require detailed information from the Idaho Transportation Department ( ITD ) traffic counts and vehicle miles traveled ( VMT ) statistics to characterize the VMT within the modeling domain , while the Source Related inputs are derived primarily from the statewide
vehi cle registration database.3

Figure 1

. Motor Vehicle Emission Simulator input files and groups

.

County

- level input files were prepared for each category, using a combination of (primarily)
local data and selected MOVES national de faults in those cases where local data are not
available or are suspected to be less reliable . This section discusses the creation of each input in turn. The input file s under discussion are listed after each section heading for clarification. For
referenc e, MOVES road types and source types (vehicles) are defined in Table 2 and Table 3

, respectively

.4

Table 2

. MOVES road type descriptions

. R oad Type Desc ription

1 Off

- n etwork

2 Rural r estricted a ccess
3 Rural u nrestricted a ccess

4 Urban r estricted a ccess

5 Urban u nrestricted a ccess
Note : Motor Vehicle Emission Simulator (MOVES)

Table 3

. MOVES source type descriptions

. MOVES Source Type Description

11 Motorcycle

21 Passenger c ar
31 Passenger t ruck

32 Light c ommercial t ruck

41 Intercity b us

42 Transit b us
43 School b us
51 Refuse t ruck

52 Single u nit s hort

- haul t ruck

53 Single u nit l ong

- haul t ruck

54 Motor h ome
61 Combination s hort

- haul t ruck

62 Combination l ong

- haul t ruck

Note : Motor Vehicle Emission Simulator (MOVES)



### 2.1 VMT

- Related Inputs

VMT inputs describe the distance traveled on different roadways by the various source types (vehicles). VMT

- related inputs include road type distribution and VMT (annual, monthly, daily, and hourly estimates ). The road type VMT distribution data set was developed from the BTPO

TDM

, and the monthly, week day /week end , and hourly VMT profiles were developed from permanent ATRs

.

2.1.1 Annual VMT HPMSVTypeYear(HPMSVtypeID, yearID, HPMSBaseYearVMT, baseYearOffNetVMT)

Annual VMT describes the total vehicle miles traveled for each Highway Performance Monitoring System ( HPMS ) vehicle type

, for each count y in the domain. To generate the annual VMT input s, ITD ATR data w ere used to generate a weekday/ weekend ratio and fleet mix for each road type, which were then applied to BTPO TDM annual average weekday VMT outputs
to estimate annual VMT.

Comparing annual VMT attributed to local roads from the TDM outp ut to ITD’s annual local
road VMT from fuels sales data indicated that the TDM does n o t underestimate VMT from local5

roads (as TDMs often do)

. Thus, a local road scale

- up factor of 1 .00 was used (i.e.

, no VMT adjustment for the local road s )

. The final TDM

- based VMT are summarized in Table 4

.

Table 4

. T ravel D emand M odel

- based annual vehicle miles traveled

. Year Vehicle Miles Traveled

2011 409,399,732

2020 454,338,514

2.1.2 Road Type

Road t ypeDistribution(sourceTypeID, roadTypeID, roadTypeVMTFraction)

The road type distribution describes the fraction of fleet miles driven on each of the four applicable MOVES road types (rural restricted, rural unrestricted, urban restricted, and urban

unrest ricted) within the modeling domain for each source (vehicle) type

. Road type distribution inputs were derived from TDM outputs provided by BTPO and ITD ATR data

. A crosswalk table in Appendix A shows the relationships between BTPO TDM road types , the HPMS/ FHWA road type s, and the MOVES roadway types. The ATR

- based traffic data and TDM outputs were
used to allocate the annual VMT for each source type to road types. When the annual road distributions were complete for the FHWA road types, the distributions we re aggregated into the
four MOVES road types.

Year 2020 road type distribution was developed from the same ITD ATR data set along with year 2020 VMT from the TDM.

2.1.3 Monthly, Daily, and Hourly VMT MonthVMTFraction(source t ypeID, isLeapYear, monthID, monthVMTFraction) DayVMTFraction(sourceTypeID, monthID, roadTypeID, dayID, dayVMTFraction) HourVMTFraction(sourceTypeID, roadTypeID, dayID, hourID, hourVMTFraction)

Temporal distribution profiles further divided the sour ce type annual VMT into finer time

i ncrements. Temporal profiles were derived from ATR data and annual VMT by FHWA road
type based on BTPO ’s TDM

.

ATR data contain hourly vehicle counts for each of five length categories or bin s

. Hourly c ounts for each length bin were converted to temporal di stributions for each MOVES vehicle type and roadway type using a c rosswalk scheme developed based on discussions with ITD and 200 9

– 20 11 Idaho statewide vehicle classification data ( Scott Fugit, ITD, pers.comm. 2012)

. The final
crosswalk table

, which maps ATR length bins to MOVES vehicle type s , is provided in Appendix

B

, and the 200 9

– 2011 classification data are provided in Appendix C. Neither ATR data nor
FHWA vehicle classification data distinguish between personal or commercial light

- duty truck trips

, a nd long

- or short

- haul heavy duty truck trips , so it was necessary to use national default fractions available in the MOVES model to make the final splits from FHWA classes to MOVES vehicle types in these categories

. For each ATR site, a full year of ATR d ata w ere processed. Hourly, weekday/weekend, and monthly statistics were calculated for each vehicle type. Finally, ATR sites were grouped based on MOVES road types

, and each site was weighted equally in constructing the final temporal profiles.6

Y ear 2020 temporal profiles for each road type were developed from the same ITD ATR data set along with year 2020 VMT.



### 2.2 Source

- Related Inputs

This group of inputs includes s ource t ype p opulation and a ge d istribution. Source

- related inputs describe and group the vehic les in the modeling domain and are compiled using a variety of data

sources ( Table 5 )

. The fleet mix distribution is a key component of on

- road mobile source emissions. The majority of vehicles are well characterized by the Idaho Department of Motor Vehicle (DMV) registration database ( Bob Thompson, ITD, pers.comm. 2012 )

. The database is
screened to en sure that only vehicles with current registrations are included, and vehicle types and ages are obtained from the v ehicle i dentification n umber (VIN) to avoid data entry errors that may occur in manually entered fields.

Table 5

. Cro sswalk between MOVES source types and data sources for source

- related MOVES input parameters.

MOVES Source Type Source

- Related Input Data Source
Motorcycle ITD

— DMV r eg istration d atabase
Passenger c ar ITD

— DMV r egistration d atabase
Passenger t ruck ITD

— DMV r egistration d atabase
Light c ommercial t ruck ITD

— DMV r egistration d atabase
Intercity b us Telep hone and e

- mail s urvey

Transit b us Telep hone and e

- mail s urvey
School b us Idaho Departm ent of Education

Refuse t ruck Telep hone and e

- mail s urvey, MOVES d efault d atabase Single u nit s hort

- haul t ruck MOVES d efault d atabase, a nnual l ocal VMT Single u nit l ong

- haul t ruck MOVES d efault d atabase, a nnual l ocal VMT

Motor home ITD

— DMV r egistration d atabase

Combination s hort

- haul t ruck MOVES d efault d atabase, a nn ual l ocal VMT

Combination l ong

- haul t ruck MOVES d efault d atabase, a nnual l ocal VMT

Notes : Idaho Motor Vehicle Emissions Stimulator ( MOVES); Idaho Transportation Department (ITD); Idaho Department of Motor Vehicles (DMV); vehicle miles traveled (VMT)

2.2.1 Source Type Population SourceTypeYear(yearID, sourceTypeID, sourceTypePopulation)

The source type population input describes the types and numbers of vehicles that make up the
fleet. Six sources of data were used to develop the source type population inputs as shown in
Table 5

. Direct population and age data w ere obtained from service providers via tele phone and e

- mail

surveys for transit and intercity buses and refuse trucks. School bus data w ere obtained from the Idaho Departmen t of Education. For motorcycle, passenger car, passenger truck, light commercial truck, and motor home source types, VIN

- decoded registration data w ere used to determine vehicle populations.7

For all other heavy duty truck source types many of the vehicles are registered in other states so local registration data are not complete

, and therefore

, the heavy duty truck populations are derived from MOVES national defaults. Thus, for single and combination haul trucks, a factor
was used to e stimate the county level source type populations using local activity data, MOVES national default activity data, and MOVES national default source type populations as shown in Equation 1

. ( )

Equation 1

. Equation used to estimate vehicle population for source types w ithout local data.

The 2010 census indicates that 89.3% of the PVNAA human population resides in Bannock County

. Thus , the Bannock County source type population from the 2011 NEI was adjusted using this human population ratio as surrogate to produce the P VNAA source type population. A very small, sparsely populated sliver of the PVNAA is located in Power County ; however

, this is a negligible portion of the total PVNAA population and that portion of the source population is also assumed to have similar characteristics to Bannock County.

DEQ a ssum ed the “ VMT per vehicle population ” is approximately constant from year to yea r, allowing 2020 sour ce typ e populations to be estimated using Equation 2 shown below: ( )

Equation 2

. Equation used to estimate vehicle population for 2020

.

2.2.2 Age Distribution AgeDistribution( S ourceTypeID, Y earID, A geID, A geFraction)

Age distributions characterize the age profile of each vehicle source type . Age distributions were developed for Bannock C ounty using VIN

- decoded vehicle registration data, refuse truck, transit and intercity bus fleet data from service providers, school bus fleet data from the Idaho Department of Education , and MOVES default s for heavy duty haul truck source types

. Because
the m ajority of PVNAA is in Bannock County, age distribution s developed for Bannock County

w ere used for PVNAA directly.

T he same age distribution developed for 2011 was used for 2020 , based on the approximation that age distribution do not change significantly from year to year

.



### 2.3 VHT

- Related Inputs

Vehicle hours traveled ( VHT ) inputs characterize the time spent and average speeds of vehicles travelling on specific road types

. This group of inputs inc ludes ramp fractions and average speed
distribution

.8

2.3.1 Ramp Fractions RampFraction(roadTypeID, rampFraction)

Ramp fraction defines the portion of VHT on roadways that contain entrance and exit ramps for restricted access roadways. Ramps are treated separately from the remainder of the freeway VHT because the sudden acceleration and deceleration that occurs on ramps results in significantly higher emissions.

Both 2011 and 2020 ramp fractions for urban freeways were calculated by aggregating VHT on

ram ps and restricted access roadways from the TDM output s then dividing ramp VHT by total restricted access roadway VHT to get the fraction of restricted access VHT attributed to ramps

.

2.3.2 Average Speed Distribution AverageSpeedDistribution(sourceTypeID, roadTyp eID

, hourDayID

, avgSpeedBinID, avgSpeedFraction )

The average speed distribution allocates the different source types (vehicles) for each roadway
type to 16 speed bins ranging from 0 to > 7 2.5 miles per hour ( mph ) ( Table 6 ). This input reflects levels of congestion on roadways. Average speed distributions were developed from TDM average daily traffic counts for each roadway segment and hourly traffic count statistics developed from detailed ATR traffic count data provided by ITD.

Table 6

. MOVES speed bins.

avgSpeedBinID avgBinSpeed avgSpeedBinDesc

1 2.5 S peed <2.5 miles per hour ( mph )

2 5 2.5 mph ≤ speed <7.5 mph

3 10 7.5 mph ≤ speed <12.5 mph

4 15 12.5 mph ≤ speed <17.5 mph

5 20 17.5 mph ≤ speed <22.5 mph

6 25 22.5 mph ≤ speed <27.5 mph

7 30 27.5 mph ≤ speed <32.5 mph

8 35 32.5 mph ≤ speed <37.5 mph

9 40 37.5 mph ≤ speed <42.5 mph

10 45 42.5 mph ≤ speed <47.5 mph

11 50 47.5 mph ≤ speed <52.5 mph

12 55 52.5 mph ≤ speed <57.5 mph

13 60 57.5 mph ≤ speed <62.5 mph

14 65 62.5 mph ≤ speed <67.5 mph

15 70 67.5 mph ≤ speed <72.5 mph

16 75 72.5 mph ≤ speed

The hourly ATR

- based traffic count profiles for each roadway type were used to estimate hourly volume on each segment . The Akcelik volume delay function ( Equation 3 ) was then used to develop the average speed distribution database for each hour. This is the same volume delay
function u sed in the B TPO’s TDM (Parsons 2012) so the emissions model is internally consistent
with the TDM.9 Equation 3 . Akcelik volume delay function.

Both 2011 and 2020 average speed distributions were developed for all four MOVES road types using TDM outputs developed by BTPO and hourly temporal profiles based on the detailed ATR
data provided by ITD

.



### 2.4 Fuel

- Related Inputs

This group of inputs includes data regarding fuel supply, fuel formulation , and alternative vehicle fuels and technology ( AVFT)

.

2.4.1 Fuel Supply FuelSupply(countyID, fuelYearID, month g roup id , fuel f ormulation id

, markets hare,

market s hare cv )

Fuel supply inputs designate the fuel formulations used by the model for each model year for each source type.

National default fuel supply in puts were used for all source types except the E10 market share

. By the end of 2011, the E10 market share in Idaho is known to have been virtually 100%

, but to
account for a small number of suppliers who were still selling gasoline with no ethanol in 2011

, a nominal market share of 99% was used for E10 with 1% assigned for ethanol

- free gasoline for

2011.

For 2020, national default fuel supply was used (i.e.

, 100% E10 market share)

.10

2.4.2 Fuel Formulation FuelFormulation(

fuelFormulationID,fuelSubtypeID,RVP,sulfurL evel,ETOHVolume,MTBEVolu me,ETBEVolume,TAMEVolume,aromaticContent,olefinContent,benzeneContent,e200,e300,BioD ieselEsterVolume,CetaneIndex,PAHContent,T50,T90 )

MOVES national default fuel formulations were judged to be reaso nable and alternative local
data ar e not readily available. Therefore, national default fuel formulations were used for all
source types for both 2011 and 2020

.

2.4.3 Alternative Vehicle Fuels and Technology AVFT(sourceTypeID, modelYearID, fuelTypeID, engTechID, fuelEngFraction)

AVFT input files in MOVES allow the user to assign source type activity by model year to vehicles with different fuel and/or engine technologies. PVNAA vehicles were modeled using a custom AVFT input file derived from VIN

- decoded registration data for Bannock County

. For vehicle types not included in the registration data, AVFT files were developed from local data
available from the tele phone and e

- mail surveys shown in Table 5

. National default AVFT was
used as a supplement whe n no local data w as available.

In 2020, the same vehicle age distribution was assumed to occur as that found in 2011 so vehicle

age zero was changed from model year 2011 to model year 2020. To match the shift in the age distribution , AVFT for 2020 was similarly shifted

.



### 2.5 Mete orology
ZoneMonthHour(monthID, zoneID, H ourID, temperature, relHumidity)

The meteorology input s include the average hourly temperature and relative humidity data for

PVNAA

. The meteorological observation data for 2011 at the Pocatello Regional Airport National Weather Service station, KPIH

, obtained from MESOWES T ( 2012) an on

- line data source described by Horel et. al (2002) w ere used to generate the meteorology input. For any time period s in which KPIH data are missing, data sets from nearby ITD stati ons , ITD25

, and

ITD46 (MESOWEST 2012)

, were used to gap

- fill the original data set

.

For the future year 2020 projections , the same meteorology input f rom 2011 was u sed

.



### 2.6 Inspection and Maintenance Programs IMCoverage(polProcessID, stateID, countyID, yearID, sourceTypeID, fuelTypeID, IMProgramID, inspectFreq, testStandardsID, begModelYearID, endModelYearID, useIMyn, complianceFactor)

There are no i nspection and maintenance ( I / M ) pr ograms in place in PVNAA during 2011

, and
no need for an I/M program is anticip ated in the foreseeable future. Thus, no I/M program is designated in the model for both 2011 and 2020.11



### 2.7 On

- R oad Retrofits

On

- roadRetrofits( P ollutant, P rocess, F uel, S ource, I nitialCalendarYear, F inalCalendarYear,

I nitialModelYear, F inalModelYear, F raction / Year, F ractionEffective)

Because adequate local data w ere not available to prepare local on

- road retrofit inputs, the
PVNAA was modeled with out local on

- road retrofits.



## 3 Me thodology: Paved Road Dust

Fugitive dust from paved and unpaved roads can be a significant source of PM 10 emissions.

Because there are no unpaved roads in PVNAA, unpaved road dust is assumed to be negligible.

T his section will focus on paved road dust.

In general, the factors that affect paved road dust emissions include the weigh t of the vehicles that drive on the roadway surface, vehicle spe ed, fine particle (silt) loading on the roadway surface available for entrainment, and precipitation on the roadway that decreases road dust
emissions. A new emission factor equation for paved road s was published in January 2011 by
EPA as the agency’s recommended method in AP

- 42 Compilation of Air Pollutant Emission

Factors (EPA 2011 b , section 13.2.1 )

. This section of the report discusses data collection and calculation using the new AP

- 42 method.

Paved road dust emissions were computed on a daily basis following the most recent AP

- 42 guidance ( EPA 2011 b ) for emission factor calculation. The emission s for each day type (weekend/weekday)

, each month and each roadway type are the product of t he emission factor
and the VMT in each day type, each month

, and on each roadway type. Therefore, for each day type, each month, and each roadway type in PVNAA, VMT, road surface silt loading, average weight of the vehicles traveling the road, and the numb er of hours with at least (0.01 in ches ) of precipitation must be determined. The following sections discuss these inputs in detail. For the

pu rposes of paved road dust calculations, winter season is defined as November 1

– February 29,
and the summer or nonw inter season is defined as April 1

– October 31. The annual emission
estimates include all 12 months. Note, road dust categories are computed only for local roads, arterials and freeways ; however

, VMT are available for the HPMS roadway types. Table 7 shows the roadway type definitions and the crosswalk relationship between the road dust roadways and HPMS roadway types.12

Table 7

. Roadway t ype d efinitions in r oad d ust c alcula tion

. Road Type for
Road Dust Road Type for Road
Dust HPMS Road Type ID HPMS Road Type

11 Rural i nterstate 11 Rural i nterstate

13 Rural a rterial 13 Rural p rincipal

a rterial

15 Rural m inor a rterial

17 Rural m ajor c ollector

19 Rural m inor c ollector

21 Rural l ocal 21 Rural l ocal

23 Urban i nterstate 23 Urban i nterstate

25 Urban f reeway/

e xpressway

27 Urban a rterial 27 Urban p rincipal

a rterial

29 Urban m inor a rterial

31 Urban c ollector

33 Urban l ocal 33 Urban l ocal

Note : Highway Performance Monitoring System (HPMS)



### 3.1 Vehicle Mile s Traveled

The VMT was generated using TDM outputs in conjunction with ITD ATR data to produce
VMT for each day type, each month , and each roadway type

. The annual VMT totals used in the
road dust calculations are the same as those used in the MOVES modeling, summarized in Table

4

, s ection 2.1.1

.



### 3.2 Road Dust Emission Factor

Paved road dust emissions were computed on a daily basis using the January 2011 A P

- 42 Compilation of Air Pollutant E mission F actor s (EPA 2011 b , section 13.2.1 , Equation 2 ), as
shown in Equation 4 below. This new version of EPA’s road dust methodology is now required for use in SIP and conformity demonstrations. The form of the emission factor equation ( Equation 4 ) accounts for the dust suppression effect of precipitation that occurs during each averaging period

.
[ ( ) ( ) ] ( ) Equation 4

. Paved r oad d ust e mission
f actor

.

w here

E ext = PM 10 or PM 2.5 emission factor in the same units as k

k = particle size multiplier (1.0 for PM 10 ) ( g rams /VMT )

sL = road surface silt loading (grams per square meter)

W = average weight of the vehicles traveling the roa d (tons)13

P = number of wet days with at least 0.01 in ches of precipitation during the averaging period (daily)

N = number of days in the averaging period (e.g.

, 28, 29, 30 , or 31 for monthly)

3.2.1 Particle Size Multipliers

The particle size multipli er variable , “ k ” in Equation 4 is used to define the fraction of total PM 10 emissions that will be classified as PM 2.5 emissions ; however

, it does not influence the total PM 10 emission quantities. The Treasure Valley Road Dust Study ( TVRDS ) conducted in 2002 (Etemezian et al

. 2002) concluded that 5.7% of the total PM 10 emissions were in the PM 2.5 size
category. The TVRDS was conducted in Ada and Canyon counties but since the data w ere

co llected in Idaho, it is assumed to better reflect reality for Idaho

- specific soils and urban areas
than the default value ( 25% ) recommended in the guidance (EPA 2011 b ) and is therefore applied

to PVNAA

. This is a minor issue for a PM 10 motor vehicle budget because the PM 2.5 is less important than the total PM 10 emission rate upon which the budget is based.

3.2.2 Silt Loading

General default silt loadings are available by the a verage d aily t raffic (ADT) category in the January 2011 emission factor methodology for paved roads (EPA 2011b). The VMT

- weighted silt loading factors are necessary for each roadway type using Equation 5

. ∑ Equation 5 . VMT

- weighted silt loading.

w here

sL = VMT

- w eighted silt loading factor
i = index from 1 to 4, which represent average daily traffic volume (ADT) categories < 500,
500

– 5

, 000, 5

, 000

– 10

, 000, and >10

, 000, respect ive ly
a = Fraction of VMT on roadway in ADT category “i”
U = Ubiquitous baseline silt loading for the summer season or ubiquitous winter baseline silt loading for the winter season , for ADT category “i”

The resulting VMT

- weighted silt loadings for both summer and winter season by roadway type
are shown in Table 8

. Th e se silt loadings w ere used for both 2011 and 2020 road dust computations

.
It should be noted that silt loadings were measured in the Pocatello and Chubb u ck area in 1996/1997 (Light 1998) and were u sed in the 2004 SIP and subsequent conformity determinations since then. However, significant changes in the antiskid treatment have occurred

in the PVNAA since 199 6 resulting from reduced sand usage and improved road dust sweeping capacity. The difference s are generally summarized in Table 9 , based on information obtained
from the Pocatello and Chubb u ck road departments ( Randy Ghezzi pers. comm. 2013 and Bryan
Hall pers. comm. 2013, respectively). The changes reduced the amount of silt on roadways by using brine pretreatment, estimated to reduce the amount of sand consumption by 50% when
used , by replacing some of the sand with road salt

, which does not produce silt , and by doubling14

the street sweeping capacity in both cities. S ignificant changes resulted in the 1 5 years between
199 6 and 2011 from the SIP

- related road sanding agreements and additional ongoing efforts

. DEQ believes the local road silt levels in the PV NAA are lower than they were in 1996/1997 and

are better represented by the more explicit new EPA method (EPA 2011 b )

, which u sed ubiquitous winter silt loadings with initial peak antiskid silt loading contributions following storms. Thus, DEQ now uses the new EPA method

, which scales up to the number of winter storms and to the traffic level on each roadway to make the current paved road dust emission
estimates.

Table 8 . Silt loadings used for paved road emission factor calculation

. Road Type Season Silt Loading Factor

Rural i nterstate Winter 0.0740

Rural i nterstate Summer 0.0359

Rural a rterial Winter 0.6550

Rural a rterial Summer 0.2030

Rural l ocal Winter 2.4

Rural l ocal Summer 0.6

Urban i nterstate Winter 0.0554

Urban i nterstate Summer 0.0282

Urban a rterial Winter 0.1669

Urban a rterial Summer 0.0713

Urban l ocal Winter 2.4

Urban l ocal Summer 0.6

Table 9

. Antiskid i mprovements to lower silt loadings in Pocatello and Chubb u ck

.
1996 2013 Pocatello (Ghezzi pers.comm. 2013)

Sand: s alt r atio 15:1 4:1

Number of s treet s weepers 2 4

Salt b rine pretreatment 0 33,000 gal lons

Chubb u ck (Hall pers. comm. 2013)

Sand: s alt r atio 5:1 3:1

Number of s treet s weepers 1 2

Salt b rine pretreatment 0 30 gal lons /lane mile

3.2.3 Average Vehicle Weight by Roadway Type

Average vehicle weight for each roadway type is derived from the vehicle type fraction on each roadway type and average vehicle weight by vehicle type. ITD ATR data w ere used to determine the vehicle type fractions traveling on each roadway type. The ATR data identif y motorcycles, passenger vehicles

, and t hree classes of heavy

- duty vehicles by length measurement ; however

, the FHWA vehicle classification statistics for Ida ho by roadway type (Appendix C) are needed to provide greater detail in vehicle classification. The average vehicle weight for each vehicle type was obtained from the MOVES default database (EPA 201 1a ) as shown in Table 10

. Source type descriptions are provided in Table 3

.15

Table 10 . Average vehicle weight by vehicle type.

SourceType
ID HPMS Vtype ID SourceType Name Source Mass (Metric Tons)

11 10 Motorcycle 0.285

21 20 Passenger c ar 1.479

31 30 Passenger t ruck 1.867

32 30 Light c ommercial t ruck 2.060

41 40 Intercity b us 19.594

42 40 Transit b us 16.556

43 40 School b us 9.070

51 50 Refuse t ruck 20.684

52 50 Single u nit s hort

- haul t ruck 7.642

53 50 Single u nit l ong

- haul t ruck 6.250

54 50 Motor h ome 6.735

61 60 Combination s hort

- haul t ruck 29.328

62 60 Combination l ong

- haul t ruck 31.404

Note : Highway Performance Monitoring System ( HPMS)

3.2.4 Precipitation D ata

The number of days with more than a trace of precipitation ( ≥ 0.01 inches) is required in the road
dust calculation . The p recipitation data w ere gathered from two sources, MESOWEST (MESOWEST 2012) described by Horel et al

. (2002) and the Western Regional Climate Center (WRCC 2012). The detail ed process used to derived the precipitation data w ere documented in
the 2012 DEQ report

, Development o f the 2011 Paved Road Dust Inventory for the National

Emission Inventory ( DEQ 2012). Beca use the majority of the PVNAA resides in Bannock County, the data for Bannock County , based primarily on the Pocatello Airport National Weather
Service station w ere used to represent the PVNAA. The days per month with more than a trace amount of precipitat ion during 2011 are shown in Table 11

. For the future year 2020, the same meteorology input s were u sed

.

Table 11

. Number of days with greater than 0.01 inches of preci pitation for each month in 2011

. County Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Bannock 8 6 16 18 14 9 3 3 2 8 7 4



## 4 Results

O n

- road mobile source and paved road dust emissions estimate result s are presented in this
section.



### 4.1 On

- R oad Mobile Source Emission Estimate s

On

- road mobile source annual emission totals are shown in Table 12 . The emission results include estimates for nitrogen oxides (NO

x ), sulfur dioxide (SO 2 ), volatile organic compounds (VOC), carbon monoxide (CO), particular matter and ammonia (NH 3 ). The PM 10 and PM 2

. 516

emission estimates in Table 11 include particulate matter from direct exhaust, brake wear

, and
tire wear and do es not include paved road dust.

Table 12

. Annual on

- road emissions in PVNAA

.

Year NO
x SO 2 VOC CO PM 10 PM 2.5 NH 3 (tons per year)

2011 1,32 3 4.4 876 9,529 64.8 51.4 17.9

2020 651 4.0 495 6,643 41.0 27.6 12.7

Notes: Portneuf Valley Nonattainment Area (PVNAA); nitrogen oxides ( NO
x ); sulfur dioxide (SO 2 ); volatile organic compound (VOC); carbon monoxide (CO); particulate matter with a diameter less than 10 microns (PM 10 ); particulate matter with a diameter less than 2.5 microns (PM 2.5 ); ammonia (NH 3 )



### 4.2 Paved Road Dust Emission Estimate s

Paved road dust annual emission s for the PVNAA are shown in Table 13

.

Table 13

. Annual paved road dust emissions in PVNAA

.

Year PM 10 PM 2.5 (tons per year)

2011 316.9 18.1

2020 337.5 19.2

Notes : particulate matter with a diameter less than 10 microns (PM 10 ); particulate matter with a diameter less than 2.5 microns (PM 2.5 )



## 5 Quality Control and Quality Assurance

Quality control was achieved by a quality assurance check of each set of inputs and the final
result for both on

- road MOVES modeling and paved road dust calculation. In general, each input was checked for internal consistency, compared with Bannock County, where majority of
PVNAA resides , and assessed for reasonableness. Input and ou tput data were graphed and analyzed to ensure that the expected vehicle population, roadway activity

, and seasonal patterns
were obt ained and that differences between PVNAA and Bannock County for 2011 and 2020 on inputs and output data set s were understood and justified

.17



## References

DEQ (Idaho Department of Environmental Quality) . 2004. Portneuf Valley PM 10 Nonattainment Area State Implementation Plan, Maintenance Plan

, and Redesignation Request

. Pocatello , ID: DEQ

.
DEQ (Idaho Department of Environmental Quality)

. 2012

. Development of the 2011 Paved Road Dust Inventory for the National Emission Inventory

. Boise, ID: DEQ.

EPA (U nited S tates Environmental Protection Agency) . 2011 a

. MOVES (Motor Vehicle Emission Simulator)

. http://www.epa.gov/otaq/models/moves/index.htm

.
EPA (U nited S tates Environmental Protection Agency). 2011b. AP

- 42 Compilation of Air
Pollutant Emission Factors

. Accessed October 2011

. http://www.epa.gov/ttn/chief/ap42/index.html

.

EPA (U nited S tates Environmental Protection Agency). 201 2

. Using MOVES to Prepare Emission Inventories in State Implementation Plans and Transportation Conformity: Technical Guidance for MOVES2010, 2010a and 2010b

, Washington, DC: EPA, Office of Transportation and Air Quality

, Transportation and Regional Programs Division. EPA

420

- B

- 1 2

- 02 8

.
Etyemezian V., H. Kuhns, J. Gillies, M. Green, J. Chow, S. Kohl, and J. Watson. 2002. The Treasure Valley Road Dust Study . Las Vegas, NV: Desert Research Institute.

Horel, J. et al. 2002

. “ Mesowest: Cooperative Mesonets in the Western United States. ” Bull.

Amer. Meteor. Soc. 83 : 211

– 225.

Light, J. 1998. Pocatello Road Dust Study Final Report . Prepared for Bannock Transportation Planning Organization

. Pocatello, I D

.

MESOWEST

. 2012

. MESOWEST Online Meteorology Tool

. Data retrieved November 2012. http://mesowest.utah.edu/

.

Pa rsons (Parsons Brinkerhoff, PB Americas, Inc.) . 2012. BTPO Travel Model User’s Guide

. Prepared for Bannock Transportation Planning Organization in Pocatello, ID . Portland,

OR: Parsons.

WRCC ( Western Regional Climate Center)

. 20 12

. 2011 Precipitation Data for all Idaho

Measurement S ites

. Reno, NV : WRCC

. http://www.wrcc.dri.edu

.18 This page intentionally left blank for correct double

- sided printing.19



## Appendix A

. Crosswalk between BTPO TDM Roa d Types,
FHWA R oadway T ypes , and MOVES Roadway Types

BTPO Road Type
ID BTPO Road Type Descriptions Area Type FHWA

Road Type Code FHWA Road

Type Description MOVES

Road Type MOVES

Road Type Description

Parked vehicles and extended idle are not included in BTPO or FHWA road types 1 Off Network

6 Interstate Rural 01 Rural Principal
Arterial

— Interstate 2 Rural
Restricted
Access 5 R amp Rural

4 Principal a rterial Rural 02 Rural Principal
Arterial

— Other

3 Rural
Unrestricted
Access 3 Minor arterial Rural 06 Rural Minor
Arterial

2 Collector Rural 07 Rural Major Collector

Rural 08 Rural Minor

Collector

1 Local Rural 09 Rural Local 0 Centroid connector Rural

6 Interstate Urban 11 Urban Principal
Arterial

— Interstate

4 Urban
Restricted
Access 5 R amp Urban

Urban 12 Urban Principal

Arterial

— Other Freeways or Expressways

4 Principal a rterial Urban 14 Urban Principal
Arterial

— Other

5 Urban
Unrestricted
Access 3 Minor arterial Urban 16 Urban Minor
Arterial

2 Collector Urban 17 Urban Collector

1 Local Urban 19 Urban Local 0 Centroid connector Urban20



## Appendix B. Crosswalk between ATR Length Bin s, FHWA
Vehicle Classes

, and MOVES Source Type s

ATR Length
Bin ATR Length Bin

Range FHWA

Vehicle
Class FHWA Vehicle Class

Description MOVES

Source Type ID MOVES Source Types

1 0

– 5.9 ft 1 Motorcycles 11 Motorcycle

2 6

– 22.9 ft 2 Passenger Cars 21 Passenger Car

3 Other Two

- Axle, Four

Tire, Single

- Unit
Vehicles 31 Passenger Truck

32 Light Commercial Truck

3 23

– 39.9 ft 4 Buses 41 Intercity Bus

42 Transit Bus

43 School Bus

5 Two

- Axle, Six

- Tire, Single

- Unit Trucks 51 Refuse Truck

52 Single Unit Short

- haul Truck

53 Single Unit Long

- haul Truck

54 Motor Home

6 Three

- Axle, Single

Unit Trucks 51 Refuse Truck

52 Single Unit Short

- haul Truck

53 Single Unit Long

- haul Truck

54 Motor Home

7 Four

- or

- More Axle, Single

- Unit Trucks 51 Refuse Truck

52 Single Unit Short

- haul Truck

53 Single Unit Long

- haul Truck

54 Motor Home

4 40

– 69.9 ft 8 Four

- or

- Less Axle, Single

- Trailer Trucks 61 Combination Short

- haul Truck

62 Combination Long

- haul Truck

9 Five

- Axle, Single

Trailer Trucks 61 Combination Short

- haul Truck

62 Combination Long

- haul Truck

10 Six

- or

- More Axle, Single

- Trailer Trucks 61 Combination Short

- haul Truck

62 Combination Long

- haul Truck

5 >70 ft 11 Five

- or

- Less Axle,
Multi

- Trailer Trucks 61 Combination Short

- haul Truck

62 Combination Long

- haul Truck

12 Six

- Axle, Multi

- Trailer
Trucks 61 Combination Short

- haul Truck

62 Combination Long

- haul Truck

13 Seven

- or

- More Axle,
Multi

- Trailer Trucks 61 Combination Short

- haul Truck

62 Combination Long

- haul Truck21



## Appendix C

. ITD Statewide Vehicle Classification DataPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

This page intentionally left blank for correct double

- sided printing.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES



## Appendix B. Procedure for R evising MVEBs for PVNAA to

R eflect MOVES and Paved Road Dust M odel
C hangesPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

This page intentionally left blank for correct double

- sided printing.1



## Procedure for R evising MVEBs for PVNAA to
R eflect MOVES and Paved Road Dust M odel
C hanges

Introduction

The 2004 State Implementation Plan (SIP) for the Portneuf Valley Non a ttainment Area (PVNAA) established motor vehicle emission budgets (MVEB) for 2005, 2010

, and 2020 (DEQ 2004) . The existing MVEBs were developed consistent with the emission inventory and attainment demonstration that showed future compliance with the National Ambient Air Quality Standar ds (NAAQS) for particulate matter with a diameter le ss than 10 microns ( PM 10 )

. The existing MVEB s established in the 2003 PVNAA SIP are shown in Table 1

.

Table 1

. Existing MVEB established in 2004 PVNAA SIP

. Year PM 10 (TPY) NO
x (TPY) VOC (TPY)

2005 897 1,575 983

2010 1,120 1,085 716

2020 1,364 514 585

Notes : motor vehicle emission budget (MVEB); Portneuf Valley Nonattainment Area (PVNAA); State Implementation Plan (SIP); particulate matter with a diameter less than 10 microns (PM 10 ) ; tons per year (TPY); nitrogen oxides (NO x ) ; volatile organic compound (VOC)

The existing budgets include on

- road mobile emissions computed using MOBILE5

, paved road dust emissions computed using the 1995 version of the AP

- 42 p aved r oad d ust emission factor methodology (EPA 1995) , and a small amount of unpaved road dust emissions from the few remaining unpaved roads in the area

. The United States Environmental Protection Agency ( EPA ) required the use of Motor Vehicle Emission Simulator ( MOVES ) (EPA 2009 , 2011a ) by March 2013 and a revised AP

- 42 p aved r oad dust methodology (EPA 2011b) by February 2013 for all SIP documents and conformity tests. As a result, the Bannock Transportation Planning Organization ( BTPO ) is required to conduct their conformity tests using the new methods . To e nsure that a model

- only change
does not cause BTPO to fail the conformity test, the Idaho Department of Environmental Quality ( DEQ ) is revis ing the existing SIP MVEBs (DEQ 2004) to reflect changes in the future year emission estimates that result strictly from the change s caused by the
model/met hod used

. The revised on

- road motor vehicle emissions were developed by DEQ in 2013 using BTPO ’s latest T ravel D emand M odel (TDM) and planning assumptions for
2011 and 2020 (DEQ 2013). The purpose of this analysis is to compute revised MVEBs for the period from 2010 to 20 20

, and for 2020 and beyond to replace the 2004 MVEBs shown

in Table 1 and to demonstrate that the revised MVEBs are equivalent to the existing MVEBs
in terms of the net PM 10 projected to be contributed to the airshed

, including PM 10 formed by the reaction of precursor gases , which produce secondary inorganic aerosol and
contribute to the total PM 10 in the a irshed. As long as the new MVEBs do not result in
greater total PM 10 contribution to the PVNAA airshed than the existing MVEBs, and the growth factors and control strategy assumptions used in the original SIP future year2

projections remain valid , such that the overall conclusions o f the SIP attainment
demonstration still hold, the other (nonmobile) categories of the emission inventory and
demonstration do not need to be revis ited (EPA 2012 a )

. 

## Development of R evised MOVES and Paved Road Dust Emission Inventory

The on

- road mobile emi ssion inventory for the PVNAA was updated for 2011 and 2020 as
described by DEQ ( 2013 ) . Emissions estimates for 2010 were not made

, however

, because
newer information was available for 2011 as a result of the 2011 National Emission Inventory (NEI) pr o

ject

. DEQ used SIP

- quality, county

- level MOVES inputs (EPA 2012b) for the 2011 NEI so that it would be adequate for SIP documentation purposes. Then in early 2013

, DEQ updated the 2011 NEI inputs to reflect activity data from the PVNAA

TDM developed by BTPO

. As a result

, the more recent 2011 emissions will be used to replace the existing 2010 MVEBs because 2010 is no lon ger of interest

, and the more recent model year is more relevant and timely. Nevertheless

, the combined growth rate for the two
cities in the PV NAA, Chubbuck and Pocatello, from 2010 to 20 11 is estimated to be 0. 6 % (US Census 2013) so the 2010 and 2011 estimates are virtually equivalent in time and population and may be considered interchangeabl e

. The SIP

- level MOVES inputs developed
for the 2011 NEI includ e source population data from the Idaho Department of Motor
Vehicles

, traffic temporal information from permanent a utomatic t raffic r ecorders and bus
and refuse truck local survey information (DEQ 2013)

. The MOVE S modeling results are shown in Table 2 for the milestone years 2011 and 20 2 0. In addition, road dust emissions are shown in Table 3 for the same two years

, estimated using the 2011 AP

- 42 p aved r oad d ust emission factor method ( EPA 2011 b ). The 2011 AP

- 42 method replaced the 1995 AP

- 42

p aved r oad d ust method in January 2011

, and EPA required its use for any work af ter February 2013

, so DEQ revise d the paved road dust emissions to be consistent with any future conformity test that BTPO conducts

. The few remaining unpaved roads that were modeled in the 2004 emission inventory have been paved since 2004 and no unpaved roa d emissions remain in the PVNAA, so unpaved road emission s are set to zero. M OVES and

AP

- 42 p aved r oad d ust PM 10 emissions are shown in Table 3 along with the tota l direct PM 10 emission s from both sources.

Table 2

. On

- road m obile s ource (MOVES) e missions for 2011 and 2020 (DEQ 2013)

. Year NO
x SO 2 VOC CO PM 10 PM 2.5 NH 3 (tons per year)

2011 1,323 4.4 876 9,529 64.8 51.4 17.9

2020 651 4 495 6,643 41 27.6 12.7

Notes: Motor Vehicle Emission Simulator (MOVES); nitrogen oxides (NO x ) ; sulfur dioxide ( SO 2 ); volatile organic compound (VOC); carbon monoxide (CO); particulate matter with a diameter less than 10 microns (PM 10 ) ; particulate
matter with a diameter less than 2.5 microns (PM 2.5 ) ; ammonia (NH 3 )3

Table 3

. Paved r oad d ust PM 10 e missions , MOVES e missions

, and t otal d irect PM 10 e missions for

m odel y ear s 2011 and 2020 (DEQ 2013)

.

Year Paved Road

Dust PM 10 (TPY) MOVES PM 10 (TPY) Total Direct PM 10

Emissions

(tons per year) (tons per year) (tons per year)

2011 316.9 64.8 382

2020 337.5 41 378

A direct comparis on of the updated MOVES and p aved road emissions (DEQ, 2013) with the existing MVEB established in the 2004 SIP is shown in Table 4 . The 2011 PM 10 emission estimates in Table 4 include the direct PM 10 emissions from MOVES ( consisting of exhaust particulate, brake wear and tire w ear ) combined with PM 10 from revised paved road dust computations (DEQ

, 2013). Only those pollutants that can significantly contribute directly to particulate matter levels in the atmosphere, or indirectly, through photochemical reactions are included in the motor vehicle budgets: Direct PM 10 , nitrogen oxides (NO

x ) and Volatile Organic Carbon c ompounds ( VOCs )

. The NO

x and VOCs form ammonium nitrate (NH 4 NO 3 ) “ secondary aerosol ” by photochemical reaction in the atmosphere. Ammonia (NH 3 ), another precursor to ammonium nitrate is not included in the motor vehicle emission budget because vehicles exhaust extremely small amounts, and it is so plentiful in the western U.S. atmosphere that it is generally considered always available for reaction and relatively invariant in the atmosphere. In addition, sulfur dioxide (SO 2 ) may contribute to
formation of the secondary aerosol ammonium sulf ate (NH 4 ) 2 SO 4 ) , however motor vehicles produce d very little SO 2 in 2004 (<1% of the total sulfur dioxide inventory) so it was not
included in the 2004 MVEBs . Lower fuel sulfur standards have resulted in even less motor
vehicle SO 2 since 2004. Carbon monoxide is a gas and plays no significant role in the photochemical production of secondary PM 10 so it too is not considered further.

In the Table 4 summary, the second column shows the emission estimates revised in 2013 in comparison to the existing MVEB in the third column. The final column shows the difference for each pollutant. Both NO

x and VOC emissions are higher in the 2011 results than the existing MVE Bs due to the change in model, while in 2020, only the NO

x emissions are higher; the VOC emissions are slightly lower. In both cases, the total PM 10 emissions are well below the existing SIP MVEB levels. This large difference results primarily from using t he more recent paved road dust estimation method and the newer silt loadings recommended by EPA in the new AP

- 42 method (EPA

, 2011), rather than the 1995

AP

- 42 method and locally measured silt loadings (Light, 199 8 ) based on measurements
made in 199 6/1997 . Significant changes in road sanding operations occurred beginning in 1995 when road sanding agreements with the local city and county road departments established a much higher level of road dust controls including salt addition to replace portions of th e sand, and street sweeping trucks to remove residual road dust after winter

storms. DEQ believes those changes in road sanding practices from 199 6 to 20 11 made the Pocatello area silt loadings comparable to other cities across the nation, a significant be nefit
of the SIP process. As a result, DEQ believes the recommended nationwide silt loadings in
the 2011 AP

- 42 p aved r oad d ust methodology are more representative of the PVNAA roadways than the 199 6/1997 silt loading measured by Light (199 8 ) prior to any s ignificant road sanding control measures. T hese revised silt loadings are more realistic because they4

account for the typically higher nationwide road silt associated with normal wintertime road sanding conditions but with silt levels that vary with the am ount of traffic (e.g.

, restricted
access interstates hav e much less silt a nd local roads hav e more )

.

The 2013 revised emissions show some reductions in direct PM 10 emissions and secondary aerosol precursors (including VOC in 2020) and some increases in secondary aerosol precursors (VOC in 2010 and NO

x in 2010 and 2020). As a result, it wa s not immediately obvious what the
net effect will be on the final airshed conc entrations of PM 10 . The following section discusses a conservative approach for reconciling the new emission estimates with the net effect the emissions will have on the airshed, thereby putting the new estimates on a common basis with the existing MVEBs f

rom the 2004 SIP.

Table 4

. Direct comparison of 2013 o n
- road e mission t otals with e xisting SIP MVEB in tons per

year (DEQ 2004)

.

Existing SIP MVEB 2013 Estimates
B ased on BTPOs
2011 TDM Difference, Existing SIP

MVEB

— 2013 Estimates

Year 2010 2011 a 2010/2011

NO
x 1,085 1,323

- 238

VOC 716 876

- 160

PM 10 1,120 382 738

Total 2,921 2,581

—
Year 2020 2020 2020

N O
x 514 651

- 137

VOC 585 495 90

PM 10 1364 379 986

Total 2,463 1,525

—

a. The 2011 year estimates are more up

- to

- date and therefore are used to rep lace 2010.
Notes : State Implementation Plan (SIP); motor vehicle emission budget (MVEB); Bannock Transportation Planning Organization (BTPO); Travel Demand Model (TDM); nitrogen oxides (NO x ) ; volatile organic compound (VOC); partic ulate matter with a diameter less than 10 microns (PM 10 ) ;



## Calculation of Net PM 10

To determine the effect of emission reductions on the PM 10 concentrations in the PVNAA airshed, the method used to demonstrate attainment in the 2004 SIP must be considered. CALPUFF dispersion modeling with chemical reaction and Speciated Linear Rollback
Model ing w ere used to demonstrate attainment in the 2004 SI P, both based on the assumption that any change in emissions for any single species , either a primary or secondary pollutant, has a directly linear effect on the concentrations of PM 10 in the airshed.
For direct PM 10 emissions, the effect on PM 10 concentra tions above the regional background level is directly proportional to the relative change in emissions. For the NO

x emissions, the actual effect is uncertain because it depend s on the rate of photochemical transformation of

NO

x into NH 4 NO 3 , a solid particl e less than 10 micrometers in size at wintertime
temperatures

. However, we can say unequivocally that the maximum amount of PM 10 that can be formed in the atmosphere from each ton of NO

x emissions can be determined based5

on stoichiometric calculations refl ecting the overall transformation process. A simplified representation of the photochemical process is shown in Equation 1

. In this process

, it should
be noted that ( a) only one NH 4 NO 3 molecule can be formed for each NO

x molecule, ( b) ammonia plays a role in forming NH 4 NO 3 but is not considered further since the atmosphere
is rich in NH 3 and thus has little effect on the extent or rate of NH 4 NO 3 formation; and ( c)

VOCs participate in the chemistry and are essential in determining the overall rate and
extent of this transformation ; however

, carbon do es not appear on the right

- hand side of the
reaction as a part of the NH 4 NO 3 parti culate formed in the atmosphere, and moto r vehicle VOCs produce no significant PM 10 in the atmosphere on their own accord.

NO

x + VOCs + NH 3 + solar UV light  NH 4 NO 3 Equation 1

. Ammonium nitrate
formation

.

Since one mole cule of NO

x (NO or NO 2 ) forms one molecule of NH 4 NO 3 , the maximum
amount of PM 10 as NH 4 NO 3 t hat can be formed from 1 ton of NO

x , under any circumstances
is therefore determined stoichiometrical ly by Equation 2 :

Tons of PM 10 as NH 4 NO 3 = tons NO

x x (80/31.6)
= tons NO

x x 2.53 Equation 2

. 100% NO
x to PM 10 formula

.

Where the ratio (80/31.6) reflects the ratio of molecular weights of NH 4 NO 3 (80) and NO

x (31.6), assuming the NO

x consists of 90% nitric oxide (NO) and 10% nitrogen dioxide (NO 2 ), the composition of NO

x emissions in the MOVES model, reflecting tail

- pipe

measurements used by EPA in the formulation of the MOVES mod el (EPA 2010)

. Thus, although 100% NO

x conversion to NH 4 NO 3 does not occur in practice, we can say with absolute certainty that it is not possible for g reater than 100% conversion and therefore, adopting it is a conservative assumption. It should be noted that there is also a night

- time mechanism for forming nitrate aerosol from NO

x emissions ; however, the same rule applies:

o ne NO

x molecule can only produce one NH 4 NO 3 molecule, and the conversion described in Equation 2 describes the maximum amount of PM 10 formed as NH 4 NO 3 regardless of the
chemical mechanism involved.

EPA ( 2008) and others ( Boylan and Kim 2012) have estimated the likely atmospheric
conversi on rates of NO

x to NH 4 NO 3 , since it is of regulatory interest when considering interpollutant trading in nonattainment areas. EPA’s initial PM 2.5 implementation guidance early in the program ( EPA 2008) suggested that a 100:1 interpollutant trading ratio ( IPTR ) ( 100 tons NO

x to 1 ton PM 2.5 ) was appropriate for the western United States ; however

, EPA
withdrew their 2008 suggested IPTRs in 2011 and required that IPTRs must be locally determined using photochemical models (McCarthy 2011 ). A recent Federal Regi ster notice (FR 41349, July 13, 2011) indicates that EPA proposes to approve a western United States
location

- specific NO

x to PM 2.5 IPTR of 9:1 for the San Joaquin Valley of California

. This is
less than one

- third of the PM 10 formation rate that correspond s to DEQ’s 100% conversion assumption (which is effectively equivalent to a 2.53:1 IPTR

, in tons NO

x :ton PM 2.5 , PM 10 being equivalent to PM 2.5 for the purposes of this discussion.) In view of the more realistic
conversion rate such as 9:1 , DEQ’s 100% conversion bounding assumption is very
conservative

. S hould it become necessary, DEQ would pursue developmen t of a local IPTR
for the PVNAA ; however

, since MVEB equivalency is confirmed assuming 100%
conversion

, such a significant effort does not currently appear necessary.6

The quantity of VOC emissions can affect the actual conversion rate of NO

x to NH 4 NO 3 , as discussed above, however, once we assume that 100% of the NO

x converts instantaneously in the atmosphere to NH 4 NO 3 , then no amount of VOC can have a ny additional effect in increasing the conversion rate or extent of conversion of NO

x in to NH 4 NO 3 or PM 10. As a result, the quantity of VOC emissions drop s out of the computation for determining the net

PM 10 production

. Thus the VOC emission budget will be the MOVES VOC estimate for the appropriate year with the same safety factors applied to the NO

x and PM 10 budgets.

Based on the above discussion of net PM 10 , t he Table 4 comparison of the 2013 emission
estimates wit h the existing MVEB from the 2004 SIP can be rearranged to show the net
effects on PM 10

. The rearranged table reflecting net PM 10 emissions due to both direct PM 10 emissions and NO

x precursor emission s is shown in Table 5

. In Table 5 , VOC is not shown
and the NO

x emissions hav e been translated ( using Equation 2 ) into secondary PM 10 . Now it is clear, from the t otal PM 10 values, that for both 2011 and 2020 model years

, the 2013 PM 10 estimates are lower than the total PM 10 associated with the MVEB established by the 2004

PVNAA SIP . T herefore

, the model changes implemented in 2013 resulted in lower net PM 10 in the airshed and are thu s approvable as a SIP revision without consideration of the overall emission inventory and without revisiting the attainment demonstration.

Table 5

. Comparison of 2013 o n
- road e missions with 2004 MVEBs in terms of net PM 10 , including primary and secondary particulate, assuming 100% N O
x conversion.

2013 Estimates
with 100% NO
x Conversion Rate Existing SIP

MVEB with 100%
NO
x Conversion
Rate Difference, Existing SIP

MVEB

— 2013 Estimates

Year 2011 2010 2010/2011

Secondary PM 10 produced from NO
x and VOC 3,347 2,745

- 602

Primary PM 10 382 1,120 738

Total PM 10 3,729 3,865 136

Year 2020 2020 2020

Secondary PM 10 produced from NO
x and VOC 1,647 1,300

- 347

Primary PM 10 379 1,364 986

Total PM 10 2,026 2,664 639

Notes: motor vehicle emission budget (MVEB); particulate matter with a diameter less than 10 microns (PM 10 ) ; nitrogen oxides (NO x ) ; volatile organic compound (VOC)



## Safety Factor

The preceding section demonstrates that the revised MVEBs resulting from EPA

- man dated changes in the on

- road and paved road dust emission models results in lower net PM 10 in the airshed. However, if the updated emissions estimates we re used directly as MVEBs

, then

any minor model input differences in future conformity tests could potentially cause the Transportation Improvement Program ( TIP ) emissions estimat es to exceed the updated budgets without any actual increase in activity or emissions . To avoid this potential7

problem, safety factors are typically built into the MVEBs to the extent that can be tolerated while still demonstrating future year NAAQS compli ance in the attainment demonstration, or in this case, without exceeding the existing MVEB . Since the e xisting SIP MVEB is
consistent with an overall emission inventory and approved attainment demonstration model showing future year compliance with the NAA QS (DEQ 2004), the revised model change MVEBs will remain consistent with the attainment demonstration as long as it does not
exceed the effective PM 10 contributed to the airshed attributed to the existing MVEB. Thus,

t he small differences shown in Table 5 between the E xisting SIP MVEB total PM 10 and the

2013 Estimates total PM 10 (136 TPY in 2010 and 639 TPY in 2020) represent extra PM 10 reductions and

, therefore, may be used to provide some minimal safety factor in the new

MVEBs . T he procedure for determining an allowable safety factor that does not cause the new MVEB to exceed the existing MVEB in term s of its net contribution to PM 10 in the airshed is represented in Table 6 through Table 8

. Again it is important to note that the extra reductions converted to safety factor come only from the lower motor vehicle emission estimates, not from other emission categories, so a reasses sment of the nonmotor vehicle emission inventory and the attainment demonstration is not required.

To en sure that the MVEB is protective for any TIP that must be evaluated during the period
from 2010 to 20 19 , it is critical to conservatively select the hig hest component for each pollutant that occurs in the period (i.e.

, from either 2010 or 2020). For VOC and NO

x , that
means that the emissions for 2011 must be used because these two pollutants are highest in
2011 and lowest in 2020. For PM 10 , the selection is not as clear because the MOVES PM 10 emissions are higher in 2011 (65 TPY ) than they are in 2020 (41 TPY ), while the road dust emissions are higher in 2020 (338 TPY ) than they are in 2011 (317 TPY )

, as shown in Table

2 and Table 3 , respectively . Thus to en sure that the highest projected direct PM 10 emissions
are used i n the MVEBs to conservatively represent any year in between the two milestone

years, the 2011 MOVES PM 10 (65 TPY ) is added to the 2020 paved road dust PM 10 (338 TPY ) resulting in a hypothetical maximum total direct PM 10 emission estimate of

403 TPY as show n highlighted in Table 6

.

To re examine the net effect on airshed PM 10 contributions after identifying the maximum emission levels for the period 2011

– 2020 ( shaded grey in Table 6 ) , we must again assume
that 100% of the NO

x may convert to PM 10 in the form of NH 4 NO 3 as shown in Table 7

. The

2011 Maximum 2013 Estimates shown in Table 7 , representing the total net PM 10 emission estimates are again lower than the existing MVEBs, now by 115 tpy, or 3. 1 % in 2011 and by 639 tpy or 31.5% in 2020. The se difference s in net PM 10 emissions may then be
translated into “ safety factor ” additions to the estimated emissions without c ausing the 2013
total PM 10 estimates to exceed the existing (2004 SIP) MVEB total PM 10

. Thus, the motor vehicle emission projections may be increased by 3 .1 % i n 2011 and 31.5% in 2020. The

2011 safety factor of 3 .1 % is not normally adequate, but since the first TIP submittal that must demonstrate conformity w ill be the 2015 TIP

, the effective safet y factor for that
model ing year, by interpolation between 3% and 31.5%

, would be approximately 13 % , a somewhat more reasonable, yet still narrow margin of safety. Nevertheless, due to other conservative features of this analysis, DEQ is confident that the se safety factor s will be adequate.8

Table 6

. Maximum emissions for the 2011

– 2020 period

.

Max imum 2013
Estimates Existing SIP
MVEB Difference

Year 201 1 2010 2010 /2011

NO
x 1,323 1,085

- 238

VOC 876 716

- 160

PM 10 403 1,120 717

Year 2020 2020 2020

NO
x 651 514

- 137

VOC 495 585 90

PM 10 379 1364 986

Table 7

. Maximum Net PM 10 emissions for the 2011

– 2020 period assuming 100% NO
x conversion

. Max imum 2013
Estimates with 100%
Conversion Rate ( TPY ) Existing SIP MVEB with 100%

Conversion Rate ( TPY ) Difference ( TPY )

Year 2011 2010 2010

Secondary PM 10 produced from
N O
x and VOC 3,347 2,745

- 602

Primary PM 10 403 1,120 717

Total PM 10 3,750 3,865 115

% Available as Safety Factor = 115 TPY /3,750 TPY = 3. 1 %

Year 2020 2020 2020

Secondary PM 10 produced from
N O
x and VOC 1,647 1,300

- 347

Primary PM 10 379 1,364 986

Total PM 10 2,026 2,664 639

% Available as Safety Factor = 639 TPY /2,026 TPY = 31.5%

Notes : particulate matter with a diameter less than 10 microns (PM 10 ) ; nitrogen oxides (NO x ) ; tons per year (TPY); State Implementation Plan (SIP); motor vehicle emission budget (MVEB); volatile organic compound (VOC)

Finally, t he explicit safety factors of 3 .1 % in 2011 and 31.5% in 2020 are applied to the
2013 emission estimates of Table 6 to provide a New SIP MVEB highlighted in Table 8

. In this table, the Maximum 2013 Estimates in Table 6 were increased, by 3% for 2011 and by 31.5% in 2020, then entered in Table 8 as the New SIP MVEB

.9

Table 8

. New SIP MVEBs including s afety f actor compared to e xisting MVEBs

.

Existing SIP
MVEB New SIP MVEB Difference,

New MVEB

— Existing MVEB

Year 2010 201 1 2010 /2011

NO
x 1,085 1,364 279

VOC 716 903 187

PM 10 1,120 415

- 705

Year 2020 2020 2020

NO
x 514 856 342

VOC 585 651 66

PM 10 1,364 498

- 866

Notes: State Implementation Plan (SIP); motor vehicle emission budget (MVEB); nitrogen oxides (NO x ); volatile organic compound (VOC); particulate matter with a diameter less than 10 microns (PM 10 )

As a final step in the process of setting new MVEBs, the new values are tested to
demonstrate that the net effect on the PVNAA airshed PM 10 levels , after applying the safety factors, will be equivalent to the existing MVEB established in the 2004 SIP. The net PM 10 is once more computed, assuming 100% conversion of NO

x to PM 10 as shown in Table 9

. Table 9 demonstrates that the total PM 10 in the New SIP MVEB budget for PVNAA is equivalent to the Existing SIP MVEB established in the 2004 SIP, as the difference bet ween the two is zero in both 2010/2011 and 2020.

Table 9

. New v ersus e xisting SIP MVEBs equivalence check in terms of n et PM 10 contribution to
PVNAA

.

Existing SIP MVEB New SIP MVEB Difference, New MVEB

— Existing MVEB

Year 2010 201 1 2010 /2011

Secondary PM 10 produced
from NO
x 2,745 3,450 705

Primary PM 10 1,120 415

- 705

Total PM 10 3,865 3,865 0

Year 2020 2020 2020

Secondary PM 10 produced from NO
x 1,300 2,167 866

Primary PM 10 1,364 498

- 866

Total PM 10 2,664 2,664 0

Notes : State Implementation Plan (SIP); motor vehicle emission budget (MVEB); particulate matter with a diameter less than 10 microns (PM 10 ); Portneuf Valley Nonattainment Area (PVNAA) ; nitrogen oxides (NO x )10



## New Motor Vehicle Emission Budget for the P eriod 2011

– 2020 and B eyond 2020

The analysis above demonstrates that model changes resulting from the use of the
MOVE S 2010b model and the 2011 p aved r oad d ust method results in new MVEBs that are equivalent to the existing MVEBs in terms of PM 10 contribution s to the PVNA A airshed.
The resulting MVEB for this period is shown in Table 10

. Conformity tests for any TIPs conducted from 2015 through 2019 will be required to meet the budget shown for 2011 ( R ecall that the 2011 PM 10 includes the maximum [ 2011 ] MOVES emissions plus the
maximum (2020) paved road dust emissions )

. A ny TIP conducted in 2020 and beyond will be required to meet the budget shown for 2020.

Table 10

. New m otor v ehicle e mission b udgets for the PVNAA

. Year PM 10 (TPY) NO
x (TPY) VOC (TPY)

2005 N/A N/A N/A

2011 415 1

, 364 903

2020 498 856 651

Notes : Portneuf Valley Nonattainment Area (PVNAA); particulate matter
with a diameter less than 10 microns (PM 10 ); tons per year (TPY); nitrogen oxides (NO x ); volatile organic compound (VOC) ; not applicable (N/A)11



## References

Boylan , J. and B. Kim

. 2012 . Development of PM 2.5 Interpollutant Trading Ratios

. P resented at 2012 EPA Regional/State/Local Modeler’s Workshop

. Chicago, I L: Georgia Environmental Protection Division, Air Protection Branch

.
DEQ (Idaho Department of Environmental Quality). 2004. P ortneuf V alley PM

10 N on

A ttainment A rea S tate Implementation P lan , Maintenance Plan and Redesignation Request

. Pocatello , ID: DEQ.

DEQ (Idaho Department of Environmental Quality). 2013. Development of the Year 2011 and Year 2020 Mobile Source Emissions Inventories for the Portneuf Valley Non

- Attainment Area, Idaho

. Boise, ID: DEQ

.

EPA (United States Environmental Protection Agency). 1995. “ Paved Road Dust .” Section

13.2 .1

. Compilation of Air Pollutant Emission Factors

. 5 th e d . Washington, DC: Office of Air Quality Planning and Standards

.

EPA (United States Environmental Protection Agen cy). 2008. PM 2.5 New Source Review Implementation Rule

. 73 F R 28339

.

EPA (United States Environmental Protection Agency). 20 09. Motor Vehicle Emission Simulator (MOVES) 2010: User Guide

. Assessment and Standards Division, Office of Transportation and Air Quality

. EPA

- 420

- B

- 09

- 041.

EPA (United States Environmental Protection Agency) . 2011 a

. MOVES (Motor Vehicle Emission Simulator)

. http://www.epa.gov/otaq/models/moves/index.htm

.

EPA (United States Environmental Protection Agency). 2011 b

. “ Paved Road Dust

. ” Section

13.2.1

. Compilation of Air Pollutant Emission Factors

. Washington, DC: Office of Air Quality Planning and Standards.

EPA (United States Environmental Protection Agency). 20 11 c

. Revised Policy to Address Reconsideration of Interpollutant Trading Provisions

. Memorandum from Gina McCarthy

. July 21.

EPA (United States Environmental Protection Agency). 201 2a

. Policy Guidance on the Use of MOVES2010 and Subsequent Minor Revisions for State Implementation Plan Development, Transportation Conformity, and Other Purposes

. Washington, DC: EPA.

EPA

- 420

- B

- 12

- 010.

EPA (United States Environmental Protection Agency). 2012 b

. Using MOVES to Prepare Emission Inventories in State Implementation Plans and Transportation Conformity:
Technical Guidance for MOVES2010, 2010a and 2010b

. Washington, DC: EPA. EPA

420

- B

- 12

- 028

.
Ligh t , J. 199 8

. Pocatello Road Dust Study Final Report

. Prepared for Bannock Transportation

P lanning Organization. Pocatello, ID.12

US Census (United States Census Bureau). 2013. Annual Estimates of the Resident Population: April 1, 2010 to July 1, 2012

. Washington, DC: United States Department of Commerce.
Accessed December 2013

. http://factfinder2.census.gov/bkmk/table/1.0/en/PEP/2012/PEPANNRES/0400000US1 6.1
6200Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES



## Appendix C

. 20 04 SIP Emission Inventory with U pdated

On

- road Mobile Emissions

Table 1

. SIP 2004 e mission Inventory with u pdated o n
- road m obile e missions (shaded)

.

Source Category Original Emissions (DEQ 2004) a Updated Emissions (DEQ 2013) b

MOBILE5 & 1995 Paved Road Dust MOVE S & 2011 Paved Road Dust

2000 EI PM 10 VOC NO
x PM 10 VOC NO
x Point 640.8 230.3 924.9

Not updated Area 980.3 1,610.1 181.9

Non

- road 41.4 255.4 823.0
On

- Road Mobile 768.6 1,186.7 1,677.8

Total 2,431.0 3,282.4 3,607.4

2005 EI MOBILE5 & 1995 Paved Road Dust

Point 622.2 106.4 538.3

Not updated Area 1,006.2 1,683.2 191.8

Non

- road 41.1 217.5 680.7
On

- Road Mobile 904.4 890.0 1,380.2

Total 2,573.8 2,897.0 2,791.0

2010 EI MOBILE5 & 1995 Paved Road Dust MOVE S & 2011 Paved Road Dust

Point 622.3 106.4 538.3 622.3 106.4 538.3

Area 1032.0 1756.3 201.7 1,032.0 1,756.3 201.7

Non

- road 40.4 183.0 596.4 40.4 183.0 596.4
On

- Road Mobile 1019.0 629.9 964.5 381.7 876.0 1,323.0

Total 2713.7 2675.5 2300.8 2,076.4 2,921.6 2,659.4

2015 EI MOBILE5 & 1995 Paved Road Dust

Point 622.2 106.4 538.3

Not updated Area 1,057.9 1,829.4 211.6

Non

- road 42.2 184.5 578.5
On

- Road Mobile 1,138.5 480.8 618.6

Total 2,860.8 2,601.1 1,947.0

2020 EI MOBILE5 & 1995 Paved Road Dust MOVE S & 2011 Paved Road Dust

Point 622.2 106.4 538.3 622.2 106.4 538.3

Area 1,089.8 1,902.5 221.5 1,089.8 1,902.5 221.5

Non

- road 44.5 195.7 579.4 44.5 195.7 579.4
On

- Road Mobile 1,258.8 415.3 452.7 378.5 495.0 651.0

Total 3,015.4 2,619.9 1,792.0 2,135.0 2,699.6 1,990.2

Notes : State Implementation Plan (SIP); Motor Vehicle Emission Simulator (MOVES); emission inventory (EI); particulate
matter with a diameter less than 10 microns (PM 10 ); volatile organic compound (VOC); nitrogen oxides (NO x )

a

. DEQ (Idaho Department of Environmental Quality). 2004. Portneuf Valley PM 10 Nonattainment Area State Implementation Plan, Maintenance Plan and Redesignation Request. Pocatello, ID: DEQ.
b

. DEQ (Idaho Department of Environmental Quality). 2013. Development of the Year 2011 and Year 2020 Mobile Source Emissions Inventories for the Portneuf Valley Non

- Attainment Area, Idaho . Boise, ID: DEQ.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES

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- sided printing.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES



## Appendix D. Public Involvement

Public NoticePortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVESPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES



### Public HearingPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVESPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVESPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVESPortneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES



### Public Comment and DEQ Response

DEQ received two comments during the public comment period held from February 14, 2014

, through March 17, 2014. No public comments were submitted during the public hearing that was held on March 11, 2014. None of the comments received raised substantive issues requiring modification to the proposed SIP.

Comment 1 : Mike (submitted via email) I'm not against clean air, Or controling pollution but lets not raise taxes or give penalties for family's or individual's that have a older car that may not meet the governments standards! A lot of people won't be able to afford more tax or a penaltie. I have never figured that equation out, your car pollutes so much so we are going to tax you or fine you!! Not sure how that fixes the problem!! It's always the same thing with government and enviromental agency's!! A new tax will fix the issue! I guess what I'm trying to say is stay out of the publics pocket!! We are all sick of the government taking our money to suppoy there little programs!! It was your Idea to add more restriction so figure out a way to do it without raising taxes!! Just stay out of my po cket!!!

Response to Comment 1 : The amendment as proposed does nothing to raise taxes nor does it give penalties or require additional restrictions. The purpose of this amendment is to revise the Portneuf Valley PM10 Nonattainment Area State Implementation Plan, Maintenance Plan, and Redesignation Request (DEQ 2004) motor vehicle emissions budget (MVEB) by incorporating emission estimates made with the Motor Vehicle Emission Simulator (MOVES), the latest United States Environmental Protection Agency (EPA)

- re quired motor vehicle emissions factor model (EPA 2009, 2011a) and with an updated road dust estimation method (EPA 2011b). The revisions in this amendment only change emission related to the MVEB and no changes are made to the point or area source emission s.

Comment 2 : This comment was received from the Bannock Transportation Planning Organization. This letter is in support of the proposed revision and requests DEQ to subm it to EPA as soon as possible.Portneuf Valley PM 10 Maintenance Plan Amendment: MOBILE6 to MOVES