Air quality is central to WFRC's work and responsibilities. Our regional transportation plan (RTP) is required to conform to the State Implementation Plan (SIP), which implements the federal air quality standards for Utah. The level of particulate matter 2.5 microns in diameter or less (PM2.5) is an area of significant concern. Fortunately, PM2.5 emissions from transportation sources are projected to decline by 52% from 2008 – 2019, due to improvements in auto technology, transit utilization, and other travel choices. Despite this progress, there is still more that we can and should do. For the past several years, our Air Quality Committee has developed and is working to implement proactive transportation-related air quality strategies that individuals, businesses and governments can use to promote clean air.
WHAT IS AIR QUALITY CONFORMITY
Air quality conformity is a federal requirement in the context of transportation plans and air quality goals. Emissions from vehicles may not exceed limits defined in the State Implementation Plan, a plan for reducing and controlling emissions in the state in order to meet federal air quality standards known as the National Ambient Air Quality standards, or NAAQS. The Regional Transportation Plan and the Transportation Improvement Program developed by WFRC must meet this air quality conformity requirement for all years defined in the Plan or TIP. This means that vehicle emissions estimated for the year 2040 may not exceed the vehicle emission budget identified in the State Implementation Plan (SIP). Failure to meet conformity requirements limits spending of federal and even local transportation funds to safety and maintenance projects, or to improvements on minor arterial and collector roads only. If conformity requirements are not met, transportation funds may not be used for adding capacity to principal arterials and freeways or to expanding fixed guideway transit facilities.
All current transportation plans for the Wasatch Front Region conform to the established SIP and its various sections. Changes will likely continue to be made to federal air quality standards which will require corresponding changes to the SIP. The Wasatch Front Region is currently in attainment (or "maintenance") for all regulated pollutants.
WHAT IS A SIP
There is a separate section in the SIP for each major regulated pollutant and each designated air quality non-attainment or maintenance area. Within the Wasatch Front Region, there are five areas that are addressed in separate sections of the SIP: Salt Lake County and Ogden City (PM10 or coarse particulate matter), Salt Lake City and Ogden City (CO or carbon monoxide), and the Salt Lake PM2.5 non-attainment area (fine particulate matter pollution control area including Salt Lake and Davis Counties and portions of Weber, Box Elder , and Tooele Counties).
In September 2006 the EPA implemented a more stringent national standard for PM2.5 of 35 μg/m3 (micrograms per cubic meter) replacing the former 65 μg/m3 standard. The range of PM2.5 measurements for the urbanized counties, including Weber, Davis, and Salt Lake, is 32–53 μg/m3. EPA designated these and other counties in Utah as PM2.5 non-attainment areas effective April 2009. With support from WFRC, the Utah Division of Air Quality has been developing a new plan (or a new section of the SIP) to reduce PM2.5 related emissions to the point that the Wasatch Front Region will once again be in compliance with national PM2.5 standards. The improved vehicle emission technology and national standards enacted in 2004 and 2007 respectively will be instrumental in the DAQ plan to achieve the new PM2.5 standard. The WFRC Regional Transportation Plan will also aid in the emission reduction effort by reducing pollution that comes from traffic congestion and by improving transit service (bus, light rail, and commuter rail) to reduce our dependence on private automobiles.
In June 2005, the original 1-hour ozone standard was revoked inasmuch as EPA has established a new 8-hour ozone standard. Salt Lake and Davis Counties are in attainment for the new 8-hour standard, so the original SIP for these has been replaced by a plan to maintain ozone related emissions at or below current levels to maintain compliance with the new standard.Utah Division of Air Quality SIP
AIR QUALITY MEMO ARCHIVE
Additional information on the Air Quality Program may be obtained by contacting Kip Billings.