1 

### Sacramento

Federal Ozone Nonattainment Area

July 24, 20142



### INTRODUCTION

The requirement to offset growth in vehicle miles traveled (VMT) is contained in the

f ederal Clean Air Act ( s ection 182(d)(1)(A) ). This section applies to areas classified as severe or extreme nonattainment of the National Ambient Air Quality Standard (NAAQS) for ozone. The Sacramento Federal Ozone Nonattainment Area is currently designate d as Severe

- 15 for the 8

- hour ozone NAAQS , and is subject to this requirement. This demonstration is included as part of the 2013 update to the Sacramento Regional 8

- Hour Ozone Attainment and Reasonable Further Progress Plan to address the requirements of Section 182(d)(1)(A).



### BACKGROUND

In 1997, U.S. EPA replaced the 1

- hour ozone standard set in 1979 with an 8

- hour standard of 0.08 ppm [ see 62 Fed.Reg. 38856 (July 18, 1997)]. The U.S. EPA promulgated rules implementing the new standard. The “Phase 1” rule was issued on April 30, 2004 (69 Fed.Reg. 23951). That rule includes anti

- backsliding requirements that meant that many requirements in place as a result of not attaining the 1

- hour
NAAQA remained applicable even after the revocation of that standard , which was

effective June 2005 (s ee 40 CFR §51.905(a)(1) and §51.900(f). In particular, an area

that was classified as Extreme for the 1

- hour standard would remain subject to the VMT emissions offset requirement even if it would not otherwise have been s ubject to that requirement based on its classification under the new 8

- hour ozone standard [40 CFR §51.900(f)(11)]. The U.S. EPA’s Phase 2 rule, issued on November 29, 2005 (70 Fed. Reg. 71612) required that areas classified as Severe or Extreme under the new 8

- hour standard would also be subject to the VMT offset requirement.



### SACRAMENTO REGION SIP SUBMISSIONS FOR VMT OFFSET

REQUIREMENT AND LITAGATION

In 2009, the 8

- hour ozone reasonable further progress plan for the Sacramento region

was submitted to U.S. EPA as required by the 1990 Amendments to the Clean Air Act. The 2009 plan addressed the requirements of Section 182(d)(1)(A) according to EPA’s longstanding interpretation that “no further TCMs are necessary if aggregate motor

vehic le emissions are projected to decline each year from the base year of the plan to the attainment year.”

Subsequent to that submission , a decision of the Ninth Circuit Court of Appeals in

Association of Irritated Residents (AIR) v U.S. EPA (reprinted as am ended on January 27, 2012, 632 F.3d 584

, 9th Cir. 2011 ) rejected EPA’s interpretation of the CAA, which had provided the basis for U.S. EPA’s approval of VMT offset demonstrations in district plans

. With the AIR decision, the Court determined that the CAA requires additional transportation control strategies and measures whenever vehicle emissions are projected to be higher than would have been had VMT not grown, even if aggregate vehicle emissions are decreasing.3



### U.S. EPA GUIDANCE ON VMT OFFSET REQUIR EMENT

In August 2012, U.S. EPA issued guidance entitled “Implementing Clean Air Act Section 182(d)(1)(A): Transportation Control Measures and Transportation Control Strategies to Offset Growth in Emissions Due to Growth in Vehicle Miles Travelled”. Among other things, U.S. EPA’s guidance points out that the Court

, in the AIR decision, omitted any reference to “transportation control strategies” (TCS). TCSs, which are not defined in the CAA or U.S. EPA regulation, are eligible to offset growth in emission s due to growth in VMT. The U.S. EPA’s new guidance indicates that technology improvements such as vehicle technology improvements, motor vehicle fuels, and other control strategies that are transportation

- related could be used to offset increases in emis sions due to VMT.

U.S. EPA’s revised guidance sets forth a method of calculating the actual growth in emissions due to growth in VMT. Essentially, the state would compare projected attainment year emissions assuming no new control measures and no VMT gro wth with projected actual attainment year emissions (including new control measures and VMT growth). If the latter number is smaller than the former, no additional transportation control measures or strategies would be required. If additional transportat ion control measures and transportation control strategies are required, they should be clearly identified and distinguished from the measures included in the initial calculations for the base year and the three scenarios identified for the attainment year

.

In addition, the guidance recommends that the base year to be used in the demonstration be the base year used in the attainment demonstration for the ozone ambient air quality standard. This Appendix includes a VMT offset demonstration in

accordance wi th U.S. EPA’s new guidance for the 8

- hour ozone requirements. To address U.S. EPA’s guidance on the base year, 2002 is used as the base year for the

1997 8

- hour standard

.



### TRANSPORTATION CONTROL STRATEGIES AND TRANSPORTATION

CONTROL MEASURES

By listing them separately, the Clean Air Act [CAA §182(d)(1)(A)] differentiates between transportation control strategies (TCS) and transportation control measures (TCM), and thus provides for a wide range of strategies and measures as options to offset

i ncreased emissions from growth in vehicle miles traveled (VMT). In addition, the example TCMs listed in Section 108(f)(1)(A) of the CAA include measures that reduce emissions by reducing VMT, reducing tailpipe emissions, and removing dirtier vehicles

from the fleet. California’s motor vehicle control program includes a variety of strategies and measures including new engine standards and in

- use programs (e.g., smog check, vehicle scrap, fleet rules, and idling restrictions). The Sacramento Area Council of Governments (SACOG) has also developed a number of TCMs to provide emission

reductions.4

Based on the provisions in Section 182(d)(1)(A) and the clarifications provided in the U.S. EPA guidance, any combination of transportation control strategies and T CMs may be used to meet the requirement to offset growth in emissions resulting from VMT growth. Since 1990 when this requirement was established, California has adopted a substantial number of enforceable transportation strategies

– more than enough to m eet the requirement to offset the growt h in emissions from VMT growth. For the 1997 8

- hour standard offset demonstration, 2002 controls are used as the base case control level since 2002 is the base year of the SIP.

A listing of the mobile source contr ol programs adopted by the State since 1990 is provided in Attachment 1. A list of SACOG TCMs implemented in the Sacramento Ozone Nonattainment Area is provided in Attachment 2.



### EMISSIONS DUE TO VMT GROWTH

As discussed above, the U.S. EPA guidance does provide a recommended calculation methodology that could be done to determine if sufficient transportation control strategies and TCMs have been adopted and implemented to offset the growth in emissions due solely to growth in VMT. As such, any increase in emissions solely from VMT increases in the future attainment year from the base year (assuming that there are no further motor vehicle control programs implemented after the base year) would need to be offset. In addition, a calculation is needed to sh ow the emissions levels if VMT had remained constant from the base year to the future attainment year. As discussed earlier, a comparison of the projected attainment year emissions assuming no new control measures and no VMT growth with projected actual a ttainment year emissions (including new control measures and VMT growth) would be made. If the latter number is smaller than the former, no additional transportation control measures or strategies would be required.



### METHODOLOGY

The following calculatio ns are based on the U.S. EPA guidance recommended calculation methodology. F or the 8

- hour ozone standard, 2002 is the base year used

for the attainment demonstration and 20 18 is the attainment year.

Analysis Tool

This analysis uses California’s approv ed motor vehicle emissions model, EMFAC. The EMFAC model estimates the emissions from two combustion processes: running exhaust and start exhaust, and four evaporative processes: hot soak, running losses, diurnal, and resting losses.

Emissions from runni ng exhaust, start exhaust, hot soak, and running losses are a function of how much a vehicle is driven. Emissions from these processes are directly related to VMT, trips, and starts. These processes are included in the calculation of the5

emissions levels used in the VMT offset demonstration. Emissions from resting loss and diurnal loss processes are not related to VMT, trips or vehicle starts and are not included in the analysis because these emissions occur regardless if the vehicle makes a trip (i.e. a start) or not.

EMFAC combines trip

- based VMT from the regional transportation planning agencies, starts data based on household travel surveys, and vehicle population data from the Department of Motor Vehicles with corresponding emission rates to calcula te

emissions

. 1

With the EMFAC model, the calculation of emissions growth and whether it is offset is simplified to a comparison of future year emissions with “no growth” in VMT or new control strategies to future emissions with VMT growth and new contr ol strategies. This follows EPA’s 2012 guidance and is consistent with the Ninth Circuit’s interpretation of CAA section 182(d)(1)(A).

The Advanced Clean Cars (ACC) regulations adopted by ARB in 2012 are not included in EMFAC 2011. The output from EMFAC 2011 was adjusted off

- model to estimate the benefits of the ACC regulations. No other off

- model adjustments were taken.

Analysis Using 2002 as the Base Year for the 1997 8

- hour Ozone Standard with

Attainment Year of 20 18

.

Step 1. Provide the emissions level for the base year.

The following table shows the VOC emissions, VMT, starts, and vehicle population for calendar year 2002 from the EMFAC2011 model.

Summary of 2002 Base Year

VMT

(thousand miles/day) Starts

(thousands / day ) Vehicle

Population

(thousands) VOC

Emissions

(tons/day)

2002 Base Year 52,595 7,935 1, 270 45

_____________________________ 1 More information on data sources can be found in the EMFAC technical document which is located on the web at: http://www.arb.ca.gov/msei/emfac2011

- technical

- documentation

- final

- updated

- 0712

- v03.pdf Step 2. Calculate three emissions levels in the attainment y ear.

For the attainment year,6

(1) Calculate emissions level with the motor vehicle control program frozen at 2002 levels and with projected VMT, starts, and vehicle population for the attainment year

. This represents what the emissions in the attainmen t year would have been if transportation control strategies and TCMs had not been implemented after 2002;

(2) Calculate emissions level with the motor vehicle control program frozen at 2002 levels and assuming VMT, starts, and vehicle population do not increase from 2002 levels; and

(3) Calculate an emissions level that represents emissions with full implementation of all transportation control strategies and TCMs since 2002 and which represents the projected future year baseline emissions inventory using the VMT, starts, and vehicle population for the attainment

year.

Calculation 1

. Calculate the emissions in the attainment year assuming no new measures since the base year, and including growth in VMT, starts, and vehicle population.

To perform this calculation, the California Air Resources Board (CARB) staff

identified the on

- road motor vehicle control programs adopted since 2002 and adjusted the EMFAC2011 to reflect the VOC emissions levels in 20 18 without the benefits of the post

- 2002 control programs. The projected VOC emissions are

28 tons/day.

Calculation 2. Calculate the emissions with no growth in VMT, starts, or vehicle population

.

EMFAC2011 allows the user to input different VMT, starts, and vehicle population than default. As such, for this calculation, the EMFAC 2011 model was run without the benefit of the post 2002 control program for calendar year 20 18 with

the 2002 level of VMT of 52,594,743 miles per day, the 2002 level of starts at
7,934,624 per day, and the 2002 level of pop ulation at 1,270,259 vehicles . The VOC emissions associated with 2002 VMT, starts, and vehicle population are

19 tons/day.

Calculation 3. Calculate emission reductions with full

I mplementation of Transportation Control Strategies & TCMs

.7

The VOC emi ssion levels for 20 18 assuming the benefits of the post

- 2002 motor vehicle control program and the projected VMT, starts, and vehicle population in

20 18 are calculated using EMFAC2011. The projected VOC emissions level is

14 tons/day. VOC emissions for t he three sets of calculations described above are provided in the following table.

Summary of 20 18 Attainment Year Emissions Levels

* 20 18 V M T bas e d on SACOG’s 2013 M TIP

** Does not include diurnal or resting loss emissions.

As provided in the U.S. EPA guidance, to determine compliance with the provisions of Section 182(d)(1)(A) of the federal Clean Air Act, the emissions levels calculated in

Calculation 3 should be less than the emissions levels in Calculation 2: Description VMT*

(miles/day,
thousands) Starts

(thousands/day) Vehicle

Population

(thousands) VOC

Emissions**

(tons/day)

(1) Emissions with

Motor Vehicle Control Program

Frozen at 2002

Levels.

(VMT, starts and vehicle
population at 20 18 levels.) 64,709 10,640 1,650 28

(2) Emissions with
Motor Vehicle Control Program

Frozen at 2002

Levels.

(VMT

, starts, and vehicle
population at 2002 l evels) 52,595 7,935 1,270 19

(3) Emissions with Full
Motor Vehicle Control Program in

Place

(VMT, starts and vehicle
population at 20 18 l evels) 64,709 10,640 1,650 148 VOC: 1 4 < 19 tons/day



### SUMMARY

The previous sections provide an analysis to demonstrate compliance with the provisions of Section 182(d)(1)(A) of the federal Clean Air Act. To further illustrate the

demonstra tion, Figure 1 below show graphically the emissions benefits of the motor vehicle control programs in offsetting VOC emissions due to increased VMT, starts, and vehicle population in the Sacramento region for the 1997 8

- hour ozone standard (2002 base year) . The left bar (in purple) shows the emissions in the base year with base year controls. The three bars on the right in each figure show the emissions levels in the attainment year for the three calculations identified above: the red bar shows attainmen t year emissions with base year controls and attainment year VMT, starts, and vehicle population, the green bar shows attainment year emissions with base year controls, VMT, starts, and vehicle population, and the blue bar shows attainment year emissions

w ith attainment year controls, VMT, starts, and vehicle population. Based on the U.S. EPA guidance, if the blue bar is lower than the green bar, then the identified transportation control strategies and TCMs are sufficient to offset the growth in

emissions

.9

F igure 1. VOC E m issions * f r om O n

- Road Mobile Sources in

the S acramento Ozone Nonattainment Area (2002 Base Ye a r )

* Does not include resting or diurnal loss emissions

X: \ VMT Offset Demonstration \ FINAL CORRECTED Sac VMT Offset Doc for EPA Reformated.docx