Division of Air Quality Air Non-Point and Mobile Sources

Fairbanks PM_2.5 SIP Model Update (2020 - ?)

DEC is currently updating the models used to support the Fairbanks PM_2.5 SIP. This is a multi-year, multi-phase effort. The content below was last updated on February 10, 2023.

• One Page Summary (Last updated April 15, 2022)
• Basic Overview of the three phases to the model development (Last updated April 15, 2022)
• Technical Modeling Report for Phase 1, 2, and 3 - (Last updated February 10, 2023)

Fairbanks PM_2.5 Serious SIP Development Process

• Preliminary Draft Documents
• Stakeholder Process and Information

Fairbanks PM_2.5 Moderate SIP Development Process

PM_2.5 NAAQS Revision from 65 µg/m³ to 35 µg/m³ in 2006

The Clean Air Act requires EPA to evaluate the National Ambient Air Quality Standards (NAAQS) for criteria pollutants every five years to determine if they are protective of public health based on current research. EPA revised the 24-hour PM_2.5 NAAQS in 2006, lowering it from 65 µg/m³ to 35 µg/m³. (71 FR 61144 (PDF))

Air Quality Monitoring

DEC's Air Monitoring Plan describing the monitoring efforts throughout Alaska are available at: Alaska Air Monitoring Plan. DEC monitored PM_2.5 air pollution in Fairbanks beginning in 2000. Graphs of 24-hour PM_2.5 concentrations at the State Office Building monitor beginning in 2000 are available at: Air Quality Trends at State Office Building Monitor beginning in 2000. Compliance with the standard is calculated using a design value, which is a three year average of the 98th percentile measured PM_2.5 concentrations. The design value for PM_2.5 concentrations recorded at the State Office Building Monitor between 2004 and 2006 was 43 µg/m³. EPA used data from this monitor when designating the Nonattainment Area.

Nonattainment Area Designation - 2009

States are required to submit recommendations to EPA on which areas EPA should classify as attaining or not attaining the standard. EPA then works with states to develop the boundaries of each Nonattainment Area. EPA initially proposed a larger area but DEC provided information supporting a smaller area. The current Nonattainment Area boundary was defined through this process.

Research and Projects

DEC worked closely with the FNSB, EPA, and other entities to conduct technical work to understand the nature and extent of the PM_2.5 problem and to quantify the contributions of individual emission sources. The agencies conducted a number of technical studies and have worked to improve the technical tools and models needed to analyze trends, sources, and controls.

Briefings to the FNSB Assembly and Other Presentations

DEC presents briefings to the FNSB Assembly to provide updates on the development of the SIP and progress towards attainment.

Regulatory and SIP Proposals, Adoption, & Submittal to EPA

DEC released regulations and the SIP in two separate proposal packages for public review and comment in 2013 and 2014. Details of these proposals including the proposed and adopted regulations, responses to comments and questions, and submittal to EPA are available on these pages:

State Implementation Plans – General Information

The Clean Air Act requires communities not in attainment to come into compliance with the NAAQS. States with Nonattainment Areas are required to submit a State Implementation Plan, or SIP, to the EPA. A SIP is an enforceable plan developed at the state and local level that explains how an area will comply with air quality standards. A SIP:

For more information on State Implementation plans, please visit the DEC's pages on:

Clean Air Act Planning Requirements for Nonattainment Areas

The State is required to develop and submit to EPA for approval an implementation plan to bring the area into attainment with the NAAQS (Clean Air Act (CAA) Sections 110 and 172). The CAA plan deadline requires submittal to EPA within three years of designation. The attainment deadline is five years from designation. The CAA requires the State and local governments to have adequate funding, personnel, and legal authority for implementation of the plan. The plan may include a mix of local, state, and federal programs to improve air quality. Both mandatory and voluntary programs are useful in reducing air pollution; however, a plan must include enforceable measures and permanent reductions of emissions sufficient to demonstrate that the community will attain the standard and maintain levels below the standard in the future.

If a State fails to develop or implement a control plan, EPA can take action through its authority to sanction states and to implement a Federal Implementation Plan. Sanctions include additional requirements to offset emissions from industrial projects and the loss of federal highway funds within the Nonattainment Area. Sanctions take effect in two steps, 18 and 24 months after EPA makes a finding of failure to plan. Failure to develop or implement a plan also creates difficulties for projects with federal funding or approvals as they must demonstrate Conformity with the state’s plan and does not conflict with the community attaining or maintaining the standard.