Air Board Oks Utah's Statewide Air Plan
The Plan Will Be Submitted to EPA for Final Approval
The Utah Air Quality Board on Dec. 4, 2013 approved the state's plan to meet federal health standards for fine particulate pollution, known as PM2.5, in areas along the Wasatch Front, following a seven year effort that involved hundreds of stakeholders and public participation.
The State Implementation Plan (SIP) will phase in many new regulations and rules that apply to not only industries and large manufacturers, but also to small businesses, homeowners and consumers.
"The SIP doesn't eliminate all pollution, but we feel it will get us where we need to be—in compliance with federal air quality standards by 2019," said Bryce Bird, director of the Division of Air Quality (DAQ). "We will start seeing improved air quality because of the rules and regulations in place."
Utah's Unique Air Shed
Utah's mountain-valley topography, diverse economy and growing population create some air quality challenges for the state.
Each year in various parts of Utah, inversions (i.e., the reverse of a normal air pattern with cooler air above and warmer air below) occur during the winter months. An inversion will linger until wind or a storm front passes through. During an inversion, the warm layer acts like a lid, trapping emissions from vehicles, businesses and industrial processes in the cold air near the valley floor. These emissions mix in the cold layer of air to form particulate matter (PM).
Prolonged inversions can lead to high levels of fine particulate pollution (PM2.5). There are two types of fine particulates: primary and secondary. Primary PM2.5 is emitted directly as a particle and enters the atmosphere as soot. Secondary particulates form when precursor emissions react in the atmosphere to create PM2.5. Most of Utah's PM2.5 pollution comes from secondary particles. For example, during winter inversions vehicles contribute more than half of the emissions that lead to the formation of PM2.5.
All states are subject to two health-based National Ambient Air Quality Standards for fine particulates: a 24-hour standard of 35 µg/m3 and an annual standard of 12 µg/m3. Utah meets the annual standard in all areas of the state. Davis and Salt Lake counties, and parts of Box Elder, Cache, Tooele, Utah and Weber counties exceed the 24-hour standard at times during the winter. As a result, the Environmental Protection Agency (EPA) has designated these areas as "nonattainment."
Development of a SIP
In 2006, DAQ initiated the development of the SIP to reduce PM2.5 emissions and bring fine particulate levels below the national standard (i.e., into attainment). It was a multi-step process:
Step 1: Emissions Inventory
First, DAQ conducted an inventory of the various sources of emissions. The identified sources are categorized as:
- Mobile (e.g., vehicles)
- Point (e.g., large manufacturers)
- Area (e.g., home and commercial heating)
The chart above is based on the DAQ 2008 emissions inventory for the four urbanized Wasatch Front counties: Davis, Salt Lake, Utah and Weber. These are average winter weekday emissions.
Step 2: Modeling & Testing
The DAQ developed a model to mimic atmospheric conditions, which was used to help test possible strategies to reduce emissions. To be included in the SIP, a strategy not only had to reduce PM2.5, but also had to meet the following criteria:
- Must be enforceable
- Must be sustainable
- Must be cost-effective
Because past SIPs have led to considerable reductions in the emissions that form PM2.5, it was challenging to find additional control strategies to lower these emissions further.
"There was no silver bullet," said Bird. "We turned to emission reduction strategies that offer smaller, incremental improvements as the means to bring these areas into attainment."
Mobile Source Strategies
Because vehicles contribute more than half of the emissions that lead to the formation of PM2.5, DAQ worked closely with stakeholder groups to gather ideas and recommendations for emission control strategies that would complement community needs.
- The combination of Tier 2 federal fleet standards and local transportation plans to reduce trips and vehicle miles travelled (VMTs) will result in up to a 50 percent reduction in vehicle emissions by 2019.
- State and regional transportation plans and programs administered by municipal planning organizations (MPOs) and the Utah Department of Transportation (UDOT) within the Salt Lake and Utah County nonattainment areas will need to conform to the allowable emission budgets in the SIP to ensure that transportation activities do not interfere with air quality progress.
Point Source Strategies
DAQ's permitting process and previous SIPs have regularly controlled emissions from point sources.
- Large manufacturing (point) sources will reduce their emissions through the installation of Best Available Control Technology (BACT) required under the SIP. Costs to install point source controls will range from $1,357 to $25,319 per ton of reduction.
- Point sources will be required to offset any future emission increases through the nonattainment area banking and trading program.
- When fully implemented, the required application of state-of-the-art emissions controls will reduce annual oil refinery emissions by more than 2,000 tons per year from current emission rates.
- Additional emission controls imposed by this SIP will result in 4,600 fewer tons per year emitted from point sources along the Wasatch Front.
Area Source Strategies
Utah's Air Quality Board has approved 23 new area source rules to reduce area source emissions, including a ban on consumer products (e.g., hair spray, air fresheners) that contain volatile organic compounds (VOC) above of the defined limits.
- Costs to install area source controls will range from $238 to $6,560 per ton. New area source rules will reduce emissions from:
- Commercial cooking
- Consumer products
- Printing and publishing
- Painting and degreasing
- Wood stoves and boilers
Step 3: Public Involvement
With more than 650 comments received from the public during the official public comment period, the PM2.5 SIP was refined and updated to represent the best effort for cleaner air in Utah. Public feedback is a critical part of the decision making process. The public was invited to provide comments and feedback on DAQ's findings and recommendations in the proposed SIP, from October 1 through October 31, as well as attend any one of three public hearings that were held in Ogden, Provo and Salt Lake City. The DAQ reviewed and made changes and adjustments to the proposed SIP based on public feedback.
The PM2.5 SIP will be reviewed by the EPA for federal approval. Utah has five years to bring all sources into compliance—based on the strategies outlined in the SIP—in order to achieve attainment of the EPA's health-based National Ambient Air Quality Standards.
See the PM2.5 SIP Development for more information.