Updated Transportation Conformity Budgets for the San Joaquin Valley Ozone, 

PM2.5, and PM10 State Implementation Plans 

Release Date: September 21, 2015

Scheduled for Consideration: October 22, 2015
This document has been reviewed by the staff of the California Air Resources Board 

and approved for publication. Approval does not signify that the contents necessarily 

reflect the views and policies of the Air Resources Board, nor does the mention of trade 

names or commercial products constitute endorsement or recommendation for use.

Electronic copies of this document are available for download from the Air Resources 

Board’s Internet site at: http://www.arb.ca.gov/planning/sip/planarea/sanjqnvllysip.htm. 

In addition, written copies may be obtained from the Public Information Office, Air 

Resources Board, 1001 I Street, 1st Floor, Visitors and Environmental Services Center, 

Sacramento, California 95814, (916) 322-2990.

For individuals with sensory disabilities, this document is available in Braille, large print, 

audiocassette, or computer disk. Please contact ARB’s Disability Coordinator at 

(916) 323-4916 by voice or through the California Relay Services at 711, to place your 

request for disability services. If you are a person with limited English and would like to 

request interpreter services, please contact ARB’s Bilingual Manager at (916) 323-7053.
Table of Contents

I. BACKGROUND........................................................................................................... 1

II. UPDATED CONFORMITY BUDGETS FOR THE OZONE, PM2.5 and PM10 PLANS 

IN THE SAN JOAQUIN VALLEY..................................................................................... 1

Updated Ozone Budgets ............................................................................................. 3

Consistency with the Ozone Plan ................................................................................ 3

Updated PM2.5 Budgets.............................................................................................. 5

Consistency with the PM2.5 Plan ................................................................................ 5

Updated PM10 Budgets............................................................................................... 6

Consistency with the PM10 Plan ................................................................................. 7

III. EMISSIONS TRADING MECHANISM................................................................... 8

IV. STAFF RECOMMENDATION ............................................................................... 8

Attachment: Budget Detail for Updated Transportation Conformity Budgets for the San 

Joaquin Valley Ozone, PM2.5, and PM10 State Implementation Plans .......................... 9
List of Tables

Table 1. San Joaquin Valley Summer Ozone Conformity Budgets ................................ 3

Table 2. Nitrogen Oxide Emissions Comparison – All Source Categories ..................... 3

Table 3. Reactive Organic Gas Emissions Comparison – All Source Categories .......... 4

Table 4. San Joaquin Valley Winter PM2.5 Conformity Budgets.................................... 5

Table 5. Nitrogen Oxide Emissions Comparison – All Source Categories ..................... 5

Table 6. PM2.5 Emissions Comparison – All Source Categories................................... 6

Table 7. San Joaquin Valley Annual PM10 Conformity Budgets.................................... 6

Table 8. Nitrogen Oxide Emissions Reductions Comparison Existing vs. Current 

Inventories –All Source Categories ................................................................................. 7

Table 9. PM10 Emissions Reductions Comparison Existing vs. Current Inventories – 

All Source Categories...................................................................................................... 7
I. BACKGROUND

Section 176(c) of the Clean Air Act (Act) establishes transportation conformity 

requirements which are intended to ensure that transportation activities do not interfere 

with air quality progress. The Act requires that transportation plans, programs, and 

projects that obtain federal funds or approvals conform to applicable State 

Implementation Plans (SIP) before being approved by a Metropolitan Planning 

Organization. Conformity to a SIP means that proposed activities must not: 

• Cause or contribute to any new violation of any standard, 

• Increase the frequency or severity of any existing violation of any standard in any 

area, or 

• Delay timely attainment of any standard or any required interim emission 

reductions or other milestones in any area. 

On November 16, 2007 the Board submitted an air quality attainment plan for the 8-hour 

ozone National Ambient Air Quality Standard (NAAQS) and a maintenance plan and 

re-designation request for the PM10 NAAQS in the San Joaquin Valley (Ozone Plan 

and PM10 Plan). On March 4, 2013 the Board submitted an attainment plan for the 

2006 PM2.5 NAAQS (PM2.5 Plan) for the Valley. The U.S. Environmental Protection 

Agency (U.S. EPA) approved the Ozone and PM10 Plans on March 1, 2012 and 

November 12, 2008 respectively. The U.S. EPA proposed approval of the PM2.5 Plan 

on January 13, 2015. The Ozone, PM10 and PM2.5 Plans all contain transportation 

conformity budgets that used the most up to date emission rates and planning 

assumptions available at the time the plans were developed.

II. UPDATED CONFORMITY BUDGETS FOR THE OZONE, PM2.5 and PM10 PLANS 

IN THE SAN JOAQUIN VALLEY

ARB staff has released a revised emission rate program, EMFAC 2014, which updates 

the emission rates and planning assumptions used in conformity budgets. Staff has 

updated the conformity budgets in the Ozone, PM10 and PM2.5 Plans to use the latest 

information. 

Section 93.124(e) of the federal conformity rule states that nonattainment areas with 

more than one Metropolitan Planning Organization (MPO) may establish motor vehicle 

emission budgets for each MPO in the nonattainment area. The Ozone, PM10 and 

PM2.5 Plans establish county-level emission budgets for each MPO in the San Joaquin 

Valley (Valley). 

Air Resources Board (ARB or Board) staff developed the proposed budgets in 

consultation with the eight Valley MPOs, U.S. EPA, and the San Joaquin Valley Air 

Pollution Control District. The transportation conformity budgets in this update use

travel activity projections provided by the Valley MPOs consistent with the 2015 Federal 

Transportation Improvement Plan (2015 FTIP).

1
The budgets have been constructed using emissions for the season consistent with the 

emissions inventory in the respective plans, i.e. summer for the Ozone Plan, winter for 

the PM2.5 Plan and annual for the PM10 Plan, using the following method:

1) Sum the county-by-county emissions results from EMFAC 2014 to get a 

Valley-wide total;

2) Round the Valley-wide totals up to:

a. the nearest whole ton for NOx and ROG;

b. the nearest tenth of a ton for PM2.5 and PM10;

3) Reallocate the rounded total Valley-wide emissions to each county 

proportional to each county’s contribution to the total; and

4) Calculate the budget by rounding each county’s emissions to the nearest 

tenth ton (for all pollutants and precursors) using conventional rounding.

The attachment to this update provides more detailed calculations.

The following sections provide the proposed budget updates using EMFAC 2014 and 

discussion of their consistency with the demonstrations of progress and attainment or 

maintenance of the NAAQS in the respective plans. Following U.S. EPA guidance, 

consistency is determined by comparing inventories of emissions in tons for plans that 

model absolute concentrations, as in the Ozone and PM2.5 plans. Consistency is 

demonstrated by examining the relative reductions in emissions inventories for plans 

that use relative modeling, as in the PM10 maintenance plan.

For each of the tables that follow, an increase in emissions in the current emissions 

inventory compared to the existing plan inventory is denoted by a negative number in 

the “Differences” columns on the right side of the tables, and a reduction in emissions in 

the current inventory is denoted by a positive number in the “Differences” column.

2
Updated Ozone Budgets

Table 1 below details the updated ROG and NOx budgets for the San Joaquin Valley 

Ozone Plan by subarea.

Table 1. San Joaquin Valley Summer Ozone Conformity Budgets 

 (Tons per summer day)*

County Subarea 2017 2020 2023

ROG NOx ROG NOx ROG NOx

Fresno 8.7 29.9 6.8 24.3 5.6 14.6

Kern (SJV) 6.9 26.8 5.7 22.4 4.8 12.9

Kings 1.4 5.5 1.1 4.7 0.9 2.7

Madera 2.0 5.5 1.6 4.5 1.3 2.7

Merced 2.7 10.3 2.1 8.5 1.7 5.1

San Joaquin 6.4 14.1 5.1 11.3 4.3 7.3

Stanislaus 4.1 11.3 3.2 9.2 2.7 5.8

Tulare 4.0 10.3 3.1 8.1 2.5 4.9

*Budgets are rounded up to the nearest tenth ton (0.1).

Consistency with the Ozone Plan

Table 2 and Table 3 below compare the emissions inventories for NOx and ROG, 

respectively from the existing Ozone Plan and the most current inventory by major 

source category. These tables show net reductions of ROG and NOx emissions for the 

reasonable rate of progress (RFP) years of 2017 and 2020, and the attainment year of 

2023. Note that the current inventory reflects the proposed budgets detailed in Table 1. 

Table 2. Nitrogen Oxide Emissions Comparison – All Source Categories

Inventory 

Category

Emissions in existing 

2008 Ozone Plan*

Current Emission 

Inventory 

Differences By Year 

(Existing – Current (tons 

per day))

2017 2020 2023 2017 2020 2023 2017 2020 2023

Stationary 57.0 57.2 56.9 31.6 30.8 30.3 25.3 26.5 26.6

Area wide 8.8 8.8 8.8 4.8 4.9 4.9 4.0 3.9 3.9

On-Road 

Mobile 115.6 91.6 69.8 113.1 92.2 55.3 2.5 -0.6 14.5

Other Mobile 89.1 80.4 72.7 89.4 81.6 70.2 -0.3 -1.2 2.5

TOTAL 270.6 238.1 208.2 238.9 209.5 160.7 31.6 28.6 47.5

* Includes 2011 Plan updates

3
Table 3. Reactive Organic Gas Emissions Comparison – All Source Categories

Inventory 

Category

Emissions in existing 

2008 Ozone Plan*

Current Emission 

Inventory 

Differences By Year 

(Existing – Current (tons 

per day))

2017 2020 2023 2017 2020 2023 2017 2020 2023

Stationary 155.4 160.0 165.0 102.4 105.4 108.6 53.0 54.5 56.4

Area wide 124.9 129.3 133.8 152.8 157.9 163.0 -27.9 -28.6 -29.1

On-Road 

Mobile 46.4 39.1 37.5 36.2 28.6 23.7 10.2 10.4 13.7

Other Mobile 57.1 56.5 57.1 37.9 35.1 32.1 19.1 21.4 25.0

TOTAL 383.8 384.9 393.4 329.4 327.0 327.4 54.5 57.9 66.0

* Includes 2011 Plan updates

Increases in area wide emissions of ROG are offset by greater reductions in stationary 

sources of ROG. The net emissions of NOx from stationary sources are reduced by 

over 25 tons per day in all years. In the RFP year of 2020 the proposed budgets and 

the other mobile category represent a small increase in NOx from mobile sources. This 

is more than offset by net reductions in NOx from stationary and area wide sources. 

The current emissions inventory is the most recent inventory being developed for the 

2016 ozone plan for the Valley. The changes between existing plan and current 

inventories can be attributed to changes in base year, updates to both the EMFAC on 

road and OFFROAD emissions models and updates to area wide estimation 

methodologies. 

4
Updated PM2.5 Budgets

Table 4 below details the updated PM2.5 and NOx budgets for the San Joaquin Valley 

PM2.5 Plan by subarea.

Table 4. San Joaquin Valley Winter PM2.5 Conformity Budgets* (Tons per winter day)

County Subarea 2017

PM2.5 NOx

Fresno 1.0 32.1

Kern (SJV) 0.8 28.8

Kings 0.2 5.9

Madera 0.2 6.0

Merced 0.3 11.0

San Joaquin 0.6 15.5

Stanislaus 0.4 12.3

Tulare 0.4 11.2

 *Budgets are rounded up to the nearest tenth ton (0.1).

Consistency with the PM2.5 Plan

Table 5 and Table 6 below compare the emissions inventories for NOx and PM2.5, 

respectively from the existing PM2.5 Plan and the most current inventory by major 

source category for the RFP year of 2017. Note that the Current Inventory reflects the 

proposed budgets detailed in Table 4

Table 5. Nitrogen Oxide Emissions Comparison – All Source Categories

Inventory 

Category

Emissions in 

existing PM2.5 

Plan*

Current 

Emission 

Inventory 

Differences By 

Year (Existing –

Current (tons per 

day))

2017 2017 2017

Stationary 27.4 28.5 -1.1

Area wide 15.6 11.7 3.9

On-Road Mobile 125.6 122.3 3.3

Other Mobile 64.3 62.9 1.4

TOTAL 232.9 225.4 7.5

 * 2012 Plan (v.1.03) including 2014 conformity budget updates.

 

5
Table 6. PM2.5 Emissions Comparison – All Source Categories

Inventory 

Category

Emissions in 

existing PM2.5 

Plan*

Current 

Emission 

Inventory 

Differences By 

Year (Existing –

Current (tons per 

day))

2017 2017 2017

Stationary 8.9 8.7 0.2

Area wide 46.8 41.2 5.6

On-Road Mobile 4.2 3.7 0.5

Other Mobile 3.6 4.1 -0.5

TOTAL 63.6 57.7 5.9

 * 2012 Plan (v.1.03) including 2014 conformity budget updates. 

The only category of emissions that shows an increase between existing and current 

inventories is stationary NOx, and this small increase is offset by reductions in area 

wide, on road and other mobile source categories. 

The current emissions inventory is the most recent inventory used in the 2015 PM2.5 

Plan for the San Joaquin Valley. The changes between exiting plan and current 

inventories can be attributed to changes in base year, updates to both the EMFAC on 

road and OFFROAD emissions models and updates to area wide source estimation 

methodologies. 

Updated PM10 Budgets

Table 7 below details the updated PM10 and NOx budgets for the San Joaquin Valley 

PM10 Plan by subarea.

Table 7. San Joaquin Valley Annual PM10 Conformity Budgets* (Tons per annual day)

County Subarea 2020

PM10 NOx

Fresno 7.0 25.4

Kern (SJV) 7.4 23.3

Kings 1.8 4.8

Madera 2.5 4.7

Merced 3.8 8.9

San Joaquin 4.6 11.9

Stanislaus 3.7 9.6

Tulare 3.4 8.4

 *Budgets are rounded up to the nearest tenth ton (0.1).

6
Consistency with the PM10 Plan

Table 8 and Table 9 below compare the emissions reductions from 2005 to 2020 in the

inventories for NOx and PM10, respectively from the existing PM10 Plan and the most 

current inventory by major source category. Note that the current inventory reflects the 

proposed budgets detailed in Table 7.

Table 8. Nitrogen Oxide Emissions Reductions Comparison Existing vs. Current 

Inventories –All Source Categories*

Inventory 

Category

Existing PM10 

Plan**

Current Emission 

Inventory 

Stationary 2.2% 51.9%

Area wide 6.7% 8.7%

On-Road Mobile 58.5% 73.5%

Other Mobile 45.8% 44.6%

TOTAL 44.1% 63.5%

 * Reductions in percent from 2005 to 2020

 ** 2007 PM10 Plan v1.00 RF994

 

Table 9. PM10 Emissions Reductions Comparison Existing vs. Current 

Inventories –All Source Categories*

Inventory 

Category

Existing PM10 

Plan**

Current Emission 

Inventory

Stationary -12.3% 4.7%

Area wide -4.9% 0.5%

On-Road Mobile 34.2% 54.4%

Other Mobile 36.5% 37.8%

TOTAL -2.0% 4.9%

 * Reductions in percent from 2005 to 2020

 ** 2007 PM10 Plan v1.00 RF994

 

For NOx, the approved PM10 maintenance plan shows reductions of 44% while the 

updated inventory shows reductions of 63%. For PM10 emissions, the approved 

maintenance plan shows a slight increase of two percent while the current inventory 

shows a reduction of almost five percent. This demonstrates that reductions of PM10 

and the precursor NOx in the updated inventory exceed those in the existing approved 

plan and are consistent with the maintenance demonstration in the approved plan. 

7
III. EMISSIONS TRADING MECHANISM

Section 93.124(b) of the federal conformity rule allows for a SIP to establish emissions 

trading mechanisms between budgets for pollutants or precursors, or among budgets 

allocated to mobile and other sources. The approved PM10 maintenance plan and the 

PM2.5 Plan proposed for approval both contain emissions trading mechanisms allowing 

trading between budgets. These budget updates do not modify the already approved 

and submitted emissions trading mechanisms.

IV. STAFF RECOMMENDATION

ARB staff has reviewed the transportation conformity budgets in this update to the 

Ozone, PM2.5 and PM10 state implementation plans and has concluded that they meet 

the applicable Act requirements. The transportation conformity budgets are consistent 

with the demonstrations of progress, attainment or maintenance in the respective plans. 

Therefore, staff recommends that the Board approve these updates to the 

transportation conformity budgets in the Ozone, PM2.5 and SIPs for the San Joaquin 

Valley and direct staff to submit these updates as a revision to the California SIP.

8
Attachment: Budget Detail for Updated Transportation Conformity Budgets for the San Joaquin Valley Ozone, 

PM2.5, and PM10 State Implementation Plans

San Joaquin Valley Draft 24 hr PM2.5 Motor Vehicle Emissions Budgets

2012 Plan for the 2006 24 hour NAAQS

(tons per winter average day)

2017 Motor Vehicle Emissions Budgets

2015 FSTIP MPO activity data 

County

PM2.5 NOx PM2.5 NOx PM2.5 NOx PM2.5 NOx PM2.5 NOx PM2.5 NOx PM2.5 NOx PM2.5 NOx PM2.5 NOx

 EMFAC2014 0.94 31.97 0.80 28.67 0.15 5.88 0.18 5.97 0.29 10.98 0.60 15.44 0.39 12.25 0.37 11.15

Total 0.94 31.97 0.80 28.67 0.15 5.88 0.18 5.97 0.29 10.98 0.60 15.44 0.39 12.25 0.37 11.15 3.71 122.31

Air Basin Total 3.8 123

Disaggregated County Totals 0.961 32.146 0.814 28.836 0.151 5.912 0.185 6.008 0.292 11.038 0.618 15.527 0.403 12.319 0.376 11.213

Budget* 1.0 32.1 0.8 28.8 0.2 5.9 0.2 6.0 0.3 11.0 0.6 15.5 0.4 12.3 0.4 11.2 3.8 123.0

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare San Joaquin Valley

Air Basin

9
Attachment - continued

San Joaquin Valley Draft 8-Hour Ozone Motor Vehicle Emissions Budgets

2008/2011 Update Plan for the 1997 8-hour Ozone Standard

(tons per summer average day)

2017 Motor Vehicle Emissions Budgets

2015 FSTIP MPO activity data 

County

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

 EMFAC2014 8.69 29.71 6.87 26.66 1.41 5.46 2.01 5.51 2.69 10.20 6.38 14.03 4.10 11.28 4.04 10.25

Total 8.69 29.71 6.87 26.66 1.41 5.46 2.01 5.51 2.69 10.20 6.38 14.03 4.10 11.28 4.04 10.25 36.19 113.08

Air Basin Total 36.2 114

Disaggregated County Totals 8.690 29.948 6.868 26.807 1.407 5.488 2.012 5.537 2.694 10.258 6.379 14.105 4.103 11.343 4.046 10.308

Budget* 8.7 29.9 6.9 26.8 1.4 5.5 2.0 5.5 2.7 10.3 6.4 14.1 4.1 11.3 4.0 10.3 36.2 113.8

2020 Motor Vehicle Emissions Budgets

2015 FSTIP MPO activity data 

County

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

 EMFAC2014 6.77 24.15 5.67 22.21 1.14 4.62 1.57 4.43 2.10 8.47 5.11 11.25 3.21 9.10 3.09 8.01

Total 6.77 24.15 5.67 22.21 1.14 4.62 1.57 4.43 2.10 8.47 5.11 11.25 3.21 9.10 3.09 8.01 28.65 92.24

Air Basin Total 28.7 93

Disaggregated County Totals 6.776 24.348 5.682 22.396 1.144 4.654 1.568 4.468 2.102 8.543 5.118 11.339 3.218 9.179 3.094 8.072

Budget* 6.8 24.3 5.7 22.4 1.1 4.7 1.6 4.5 2.1 8.5 5.1 11.3 3.2 9.2 3.1 8.1 28.7 93.0

2023 Motor Vehicle Emissions Budgets

2015 FSTIP MPO activity data 

County

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

 EMFAC2014 5.56 14.40 4.82 12.71 0.94 2.68 1.27 2.66 1.71 5.07 4.29 7.18 2.65 5.78 2.48 4.87

Total 5.56 14.40 4.82 12.71 0.94 2.68 1.27 2.66 1.71 5.07 4.29 7.18 2.65 5.78 2.48 4.87 23.71 55.34

Air Basin Total 23.8 56

Disaggregated County Totals 5.583 14.570 4.837 12.858 0.942 2.714 1.270 2.690 1.712 5.132 4.302 7.261 2.660 5.845 2.493 4.930

Budget* 5.6 14.6 4.8 12.9 0.9 2.7 1.3 2.7 1.7 5.1 4.3 7.3 2.7 5.8 2.5 4.9 23.8 56.0

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare San Joaquin Valley

Air Basin

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare San Joaquin Valley

Air Basin

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare San Joaquin Valley

Air Basin

10
Attachment – continued

San Joaquin Valley Draft PM-10 Motor Vehicle Emissions Budgets

2008 Maintenance Plan for the 1987 PM-10 Standard

(tons per annual average day)

2020 Motor Vehicle Emissions Budgets

2015 FSTIP MPO activity data 

County

PM10 NOx PM10 NOx PM10 NOx PM10 NOx PM10 NOx PM10 NOx PM10 NOx PM10 NOx PM10 NOx

 EMFAC2014 1.86 25.30 1.63 23.30 0.31 4.82 0.38 4.65 0.58 8.85 1.31 11.90 0.80 9.57 0.74 8.41 7.61 96.80

Paved Road Dust 4.24 4.57 0.96 1.57 1.40 2.99 1.31 1.70

Unpaved Road Dust 0.60 0.34 0.42 0.51 1.27 0.11 0.27 0.76

Road Construction Dust 0.34 0.85 0.07 0.08 0.55 0.16 1.36 0.22

Total 7.04 25.30 7.39 23.30 1.76 4.82 2.53 4.65 3.81 8.85 4.58 11.90 3.75 9.57 3.42 8.41 34.27 96.80

Air Basin Total 34.3 97

Disaggregated County Totals 7.045 25.352 7.398 23.348 1.761 4.830 2.536 4.660 3.808 8.868 4.579 11.925 3.748 9.590 3.425 8.427

Budget* 7.0 25.4 7.4 23.3 1.8 4.8 2.5 4.7 3.8 8.9 4.6 11.9 3.7 9.6 3.4 8.4 34.3 97.0

San Joaquin

Air Basin

Fresno Kern Kings Madera Merced Stanislaus Tulare San Joaquin Valley

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OCTOBER 2015 BUDGETS UPDATE STAFF REPORT.DOCX

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