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Control Strategies:
Serious Area PM2.5 SIP


The Serious PM2.5 SIP Development is very much an iterative process. The technical foundation of any SIP involves numerous emissions inventories, air quality modeling assumptions, potential emission controls, and ever-fluctuating design values recorded throughout the air monitoring network. The PM2.5 Implementation Rule is very prescriptive about how these numbers must fit together to comprise an approvable plan. Various components are compiled early in the process only to be pieced together with other components later in the process. Corrections and adjustment to the various pieces is almost always necessary – even right up to the very end. Nothing appearing in these Serious PM2.5 SIP development pages during the process of SIP development is to be regarded as a final product. The UDAQ is making this DRAFT work available for public review in an effort to ensue transparency throughout the SIP development process. We encourage the public to review and provide feedback on these intermediary products with the understanding that they are not yet final.


The Clean Air Act (the Act) requires EPA to establish National Ambient Air Quality Standards (NAAQS) to protect human health and the environment. The Act also delegates authority to the states to develop enforceable plans, known as State Implementation Plans (SIPs), to achieve those NAAQS.

In 2014, Utah developed SIPs designed to reduce fine particulate matter (PM2.5) in three Moderate PM2.5 nonattainment areas: Salt Lake City, Provo, Logan, Utah-Idaho. The Moderate area SIPs aimed to achieve the NAAQS by implementing air pollution control strategies to reduce pollution from point, area, and mobile sources. The SIPs required sources from each of these categories to use reasonably available control measures (RACM), as required by the Clean Air Act, to reduce PM2.5 and its precursor pollutants.

With the reclassification of Utah’s PM2.5 Moderate nonattainment areas to Serious nonattainment areas, the Division of Air Quality (DAQ) is once more developing SIPs to control PM2.5 pollution from point, area, and mobile sources. Serious Area SIPs require sources from each category to implement best available control measures (BACM). BACM is more stringent than RACM, and it may achieve greater reductions in PM2.5 and its precursor pollutants than do the RACM control measures currently in the Moderate area SIPs. An overview of the types of controls that may be included in the Serious area SIPs is included below.

Point Sources

Point sources specifically identified in the Moderate area SIPs will need to ensure that their controls meet Best Available Control Measures (BACM), including Best Available Control Technology (BACT). Sources that emit 70 tons per year (tpy) or more of PM2.5 or any PM2.5 precursors — nitrogen oxides (NOx), volatile organic compounds (VOCs), sulfur dioxide (SO2), and ammonia — will be subject to BACT. In addition, sources that meet or exceed the 70 tpy threshold for a single precursor will be reclassified as major sources subject to Title V permit regulations. Under the Serious Area SIP requirements, point sources will have to undergo an updated review of control techniques to ensure all controls meet BACT. DAQ will identify best available controls to limit emissions of direct PM2.5, NOx, SO2 and VOCs, and draft new permit limits based upon those controls and control techniques. Potential control strategies for ammonia may or may not be required. The efficacy of ammonia controls with respect to reducing PM2.5 will be evaluated using the air quality model as part of the SIP.

DAQ has solicited a BACT analysis from each major point source in the PM2.5 nonattainment areas. The analyses submitted for DAQ’s review are available for public review in the links below. The division will review each of the BACT reports submitted by the sources and do its own analysis of them. The DAQ staff analysis will include the selection of BACT for the emission units at each major source. The DAQ analysis will be included in the technical support document (TSD) for the Serious SIPs and will be made available for public comment after the Air Quality Board proposes the SIPs for public comment.

Point Source Control Strategies by Source-Specific BACT Analysis

Staff Reviewed BACT Analyses for the Provo Nonattainment Area Point Sources

Staff Reviewed BACT Analyses for the Salt Lake Nonattainment Area Point Sources


Appendix A—PM2.5 Serious SIP BACT for Small Source


In accordance with 40 CFR 51.1010, the Utah Division of Air Quality (DAQ) must identify all sources of direct PM2.5 emissions and all sources of PM2.5 precursors within the PM2.5 nonattainment areas in the State of Utah. The DAQ is then required to perform a Best Available Control Technology (BACT) review for all major sources within the PM2.5 nonattainment areas in the State of Utah. As the DAQ reviewed emissions inventories of major sources (>70 tons per year PM2.5 or any PM2.5 precursor), minor source categories were identified. These source categories are emission units at multiple major sources. Rather than conduct repetitive reviews of these common source categories, the DAQ is addressing BACT for these minor sources in this appendix.

Each emission unit is addressed in its own section. Each section includes a brief description of the emission unit and the estimated emissions from the emission unit. Since emission units may vary in capacity and emission rates, the DAQ made several assumptions in determining emission estimates. In certain cases, emission factors were used instead of hourly or annual emission rates.

The BACT analysis for each emission unit includes the five steps in a top-down BACT analysis. The first step identifies control options. DAQ evaluated various resources to identify the various controls and emission rates. These include, but are not limited to, federal regulations, Utah regulations, regulations of other states, RACT/BACT/LAER clearinghouse (RBLC), issued permits, and emission unit vendors.

The second step in the BACT analysis eliminates the technological infeasible controls. The remaining control options are ranked in the third step of the BACT analysis. Combinations of various controls are also included. The fourth step of the BACT analysis evaluates the economic feasibility of the highest ranked option. This evaluation includes energy, environmental, and economic impacts of the control option.

The fifth step in the BACT analysis selects the “best” option. This step also includes the necessary justification to support the DAQ’s decision. The DAQ has included the time it will take for a source to implement the selected control if the control is not already being implemented at the source.

Area Sources

Area sources are a collection of smaller stationary sources of air pollution that do not reach an emissions threshold of 70 tpy and would be too numerous to otherwise warrant source-specific attention in the SIP. Control strategies that apply to area sources are made applicable through air quality rules that apply to every source within a particular area source category. Examples of area sources include drycleaners, restaurants, homes, and other locations that conduct activities that result in the release of air pollutants. Some of these activities include industrial processes, solvent utilization, waste disposal, and combustion activities.

DAQ developed and reviewed area-source rules for the Moderate SIP to ensure they met RACM requirements. As part of the Serious SIP, the division is reevaluating these rules to ensure they meet BACM requirements and modifying them where appropriate. DAQ will also continue to evaluate the emissions inventory to identify additional area-source categories for which new area-source rules would be appropriate. Any such rules would be required to meet BACM.

Any new rule or modification will go through the standard public review and comment process and be submitted with the Serious SIP as part of the control strategies.

Area Source Rules that will be included in the SIP

  • R307-202 Emission Standard: General Burning
  • R307-204 Emission Standard: Smoke Management
  • R307-208 Outdoor Wood Boilers
  • R307-221 Emission Standard: Emission Controls for Existing Municipal Solid Waste Landfills
  • R307-230 NOx Emission Limits for Natural Gas-Fired Water Heaters
  • R307-302 Solid Fuel Burning Devices
  • R307-303 Commercial Cooking
  • R307-304 Industrial Solvent Use
  • R307-307 Road Salting & Sanding
  • R307-309 Fugitive Emissions & Fugitive Dust
  • R307-312 Aggregate Processing Operations
  • R307-328 Gasoline Transfer and Storage
  • R307-335 Degreasing
  • R307-341 Cutback Asphalt
  • R307-342 Adhesive and Sealants
  • R307-343 Emissions Standards for Wood Furniture Manufacturing Operations
  • R307-344 Paper, Film & Foil Coating
  • R307-345 Fabric & Vinyl Coating
  • R307-346 Metal Furniture Surface Coating
  • R307-347 Large Appliance Surface Coating
  • R307-348 Magnet Wire Coating
  • R307-349 Flat Wood Panel Coating
  • R307-350 Miscellaneous Metal Parts & Products Coating
  • R307-351 Graphic Arts
  • R307-352 Metal Containers, Closure & Coil Coating
  • R307-353 Plastic Parts Coating
  • R307-354 Auto body refinishing
  • R307-355 Control of Emissions from Aerospace Manufacture & Rework Facilities
  • R307-356 Appliance Pilot Light
  • R307-357 Consumer Products
  • R307-361 Architectural Coatings

DRAFT Area Source BACM Analyses by Nonattainment Area

Mobile Sources

Mobile sources of pollution include emissions that come from motor vehicles, locomotives, construction equipment, and other combustion engines that are used for the purpose of moving from one location to another. Mobile sources are divided into two categories, motor vehicles (on-road mobile) and non-road engines.

Mobile source controls may include the use of Tier 3 fuels and vehicles and vehicle inspection and maintenance (I/M) programs. Transportation-related conformity requirements will affect Metropolitan Planning Organizations (MPOs) in nonattainment areas. PM2.5-related emission goals known as Motor Vehicle Emission Budgets (MVEBs) will be included in each SIP. To receive federal funding, each MPO will need to demonstrate conformity with these MVEBs as part of the SIP’s transportation-planning requirements.