Sacramento Regional
Clean Air Plan Update

Background   Our clean air plan (also called the State Implementation Plan, or SIP), was adopted in 1994 in compliance with the 1990 Amendments to the Federal Clean Air Act. At that time, our region could not show that we would meet the federal 1-hour standard by 1999. In exchange for moving the deadline to 2005, the region accepted a designation of “severe nonattainment”, with additional emission requirements on stationary sources. In July 1997, EPA promulgated a new 8-hour standard for ozone. This change would lower the standard for ambient ozone from 0.12 parts per million of ozone averaged over one hour to 0.08 parts per million of ozone averaged over eight hours. In general, the 8-hour standard is more protective of public health and more stringent than the federal 1-hour standard. Key aspects of the 8-hour ozone rule are the new designations and nonattainment classifications in June 2004, and the revocation of the 1-hour ozone standard in June 2005. However, the new rule also addresses anti-backsliding provisions in the Clean Air Act, so 8-hour ozone nonattainment areas remain subject to control measure commitments that applied under the 1-hour ozone standard. The Sacramento region has been designated as a “serious” nonattainment area for the federal 8-hour ozone standard with an attainment deadline of June 2013.

The Sacramento Federal Nonattainment Area The Sacramento Federal Nonattainment Area for ozone includes all of Sacramento and Yolo Counties, and portions of El Dorado, Placer, Sutter and Solano Counties (see map). Back to Top

 Transportation Conformity

Transportation conformity is the federal regulatory procedure for linking and coordinating the transportation and air quality planning processes.  Conformity provisions require that federal funding and approvals are only given to those transportation plans and projects that are consistent with air quality goals specified in state implementation plans (SIPs).  Conformity with the SIP means that emissions from transportation activities are at or below the motor vehicle emission budgets established in the SIPs.

Transportation conformity budgets were included in the Sacramento region's 8-hour ozone reasonable further progress plan^[1] for 2008.  These motor vehicle emissions were based on ARB’s improved emission factors (EMFAC2002version2.2, Apr 03) and the travel activity projections prepared by the Sacramento Area Council of Governments (SACOG).

In the March 14, 2006 Federal Register, EPA found that the motor vehicle emissions budgets for 2008 were determined to be adequate for transportation conformity purposes by the United States Environmental Protection Agency.  SACOG was able to demonstrate that the 2006 Metropolitan Transportation Plan and the 2006/08 Metropolitan Transportation Improvement Program for the Sacramento region were below the 2008 budgets.

The Sacramento Regional Nonattainment Area 8-Hour Attainment Demonstration Plan currently being developed will update the allowable motor vehicle emissions budgets for ROG and NOx for 2008 using the new EMFAC model (EMFAC2007) and population and travel activity figures. In addition, it will establish new budgets for several other years up to and including the attainment deadline year. After EPA finds these new budgets adequate, then SACOG must demonstrate that emissions from subsequent transportation plans will be below the emission budget levels established in this new air quality plan.

[1] Sacramento Regional Nonattainment Area 8-Hour Ozone Rate-of-Progress Plan (Final Report, February 2006).

Where does our pollution come from? The emission inventory chart projects 2005 summer emissions in the Sacramento Nonattainment Area as documented in the Sacramento Regional Nonattainment Area 8-Hour Ozone Rate-of-Progress Plan, December 2005. Stationary and area-wide emissions were generated by CARB's emission forecasting model, California Emission Forecast System (CEFS), Version 2.12, in the June 2004 run using 1999 base year inventory. It includes reductions from district, state and federal control measures adopted as of November 2003.  On-road emissions are based on EMFAC2002, version 2.2, with June 2005 MVSTAFF adjustments.  Emission benefits from CARB I/M, SECAT and Land Use are also incorporated to the on-road inventory by external adjustments.   Off-road and farm equipment under Other Mobile are based on the June 2003 OFFROAD model run. Aircraft emissions were updated in July 2005 to incorporate forecasted activities from Draft Final Sacramento International Airport Master Plan, February 19, 2004, and Mather Airport Master Plan Revised Draft, February 2004. Additional 2005 inventory information is available on the 2005 Emission Inventory page. Back to Top

Our ozone trends are good, the overall rate of population exposure to ozone is down, and the number of days and hours over the standard are also trending down. The annual peak number of days exceeding the federal 8-hour ozone standard at any individual monitoring site in the region has averaged about 27 per year over the last 10 years. In 2004, there were 10 exceedance days at the peak site. The air monitoring stations located at downwind foothill sites (such as, Cool, Folsom, Placerville, and Auburn) generally measure the majority of the 8-hour ozone exceedances. Note that the federal 8-hour ozone standard requirements could allow for an average of 3 exceedance days per year at any monitoring site.

The air districts of the region have adopted more than 25 rules to reduce emissions from stationary sources. Fleet turnover with new cleaner motor vehicles has also resulted in less air pollutants from mobile sources despite increasing population and vehicle travel in the region. Overall, the emissions of ozone-forming pollutants (reactive organic gases and nitrogen oxides) from human-caused sources have declined about 30% over the last 10 years. However, to attain the 8-hour ozone standard, significant additional emission reductions will be needed.

 What are our planning responsibilities?

When U.S. EPA adopts the implementation regulations for the 8-hour ozone standard, it will trigger two planning scenarios:

• A Rate of Progress (ROP) Plan will demonstrate how the air districts’ efforts will meet emission reduction targets during the early years of implementing the 8-hour standard (through 2008). The ROP Plan will show a 3% per year emission reduction in volatile organic compounds (or the NOx equivalent) for 6 years. This plan may include control measures. If allowed by EPA, the plan may establish a new Motor Vehicle Emissions Budget (MVEB), prior to the end of 2005. If approved, this could lift the conformity lapse.
• An 8-hour attainment plan will contain sufficient control measures to demonstrate that the region will attain the 8-hour standard by the target date. The plan will result in a new MVEB.

Discussion of Voluntary Reclassification Request (Bump-up)

The Sacramento region was classified by EPA as a “serious” nonattainment area on June 15, 2004, for the federal 8-hour ozone standard with an attainment deadline of June 15, 2013.  Emission reduction needs to achieve the air quality standard were identified using an air quality modeling analysis.  An evaluation of proposed new control measures and associated VOC and NOx emission reductions concluded that no set of feasible controls were available to provide the needed emission reductions before the attainment deadline year. Given the magnitude of the shortfall in emission reductions, and the schedule for implementing new control measures, the earliest possible attainment demonstration year for the Sacramento region is determined to be the “severe” area deadline of 2019.

Section 181(b)(3) of the Clean Air Act (CAA) permits a state to request that EPA reclassify a nonattainment area to a higher classification and extend the time allowed for attainment.  This process is appropriate for areas that must rely on longer-term strategies to achieve the emission reductions needed for attainment. 

The Board of Director’s for each of the five air districts which comprises the Sacramento Federal Nonattainment Area (SFNA) requested that the California Air Resources Board (CARB) submit a formal request for voluntary reclassification from a “serious” to a “severe” for the 8-hour ozone nonattainment area with an associated attainment deadline of June 15, 2019.  CARB submitted that request on February 14, 2008.

District resolutions

• Sacramento Metropolitan AQMD (PDF)
• Feather River AQMD (PDF)
• El Dorado County AQMD (PDF)
• Placer County APCD (PDF)
• Yolo Solano AQMD (PDF)

Failure to Submit

On March 24, 2008, the USEPA published in the Federal Register a finding of Failure to Submit the 2011 Reasonable Further Progress Plan for the SFNA in the Federal Register. The link to the Federal Register can be found below. The Failure to Submit finding triggered sanctions clocks, which include:

1. Offset sanctions: More stringent emission mitigation requirements for new and modified businesses, "major stationary sources" if a complete plan is not submitted within 18 months after EPA findings of failure to submit the plan.
2. Federal Highway funding sanctions: Prohibiting transportation projects from receiving federal transportation funding if a complete plan is not submitted within 24 months after EPA findings.

The sanctions clocks will stop once the Air Districts submit the 2011 Reasonable Further Progress Plan and the USEPA accepts the plan as complete.

Link: Federal Register Vol 73 No. 57 (Finding of Failure to Submit State Implementation Plan for the 1997 8-Hour Ozone NAAQS)

USEPA Finding of Failure to Submit (PDF) March 17, 2008

Reasonable Further Progress Plan

District resolutions

• Sacramento Metropolitan AQMD (PDF)
• Feather River AQMD (PDF)
• El Dorado County AQMD (PDF)
• Placer County APCD (PDF)
• Yolo Solano AQMD - pending

 What is the timeline for developing the Clean Air Plan Update?

8-hour Reasonable Further Progress (RFP) and Attainment Plan Public Process Schedule

The schedule depicted below must follow USEPA final rulemaking on the 8-hour ozone implementation rule and the conformity rule.