Background
Anchorage Alaska, was first declared a nonattainment area for carbon monoxide (CO) on January 27, 1978.

The Municipality of Anchorage (MOA) prepared its first plan to attain the National Ambient Air Quality Standards (NAAQS) by December 31, 1987. The plan was later revised in 1995 following the 1990 amendment to the Clean Air Act.

The MOA submitted a new attainment plan on January 4, 2002, and it was approved by the EPA on June 3, 2002(67 FR 58711 (PDF)(2 pp, 132 K). The MOA submitted a maintenance plan on February 18, 2004. 

On February 18, 2004, the State of Alaska submitted a carbon monoxide (CO) maintenance plan for the Anchorage CO nonattainment area to EPA for approval, and it was approved by the EPA on June 23, 2004 (69 FR 34935 (PDF)(3 pp, 147 K).

The State of Alaska submitted revisions to the Alaska SIP relating to the motor vehicle inspection program in Anchorage. The revisions were approved by EPA in two separate actions: 

1. A March 29, 2002, SIP revision that contained minor revisions to the statewide I/M program, and a December 11, 2006, submittal contained more substantial revisions to the statewide I/M program. EPA approved the revision on March 22, 2010 (75 FR 13436 (PDF)(6 pp, 159 K). 
2. A September 29, 2010, SIP revision that discontinued the I/M program in Anchorage as an active control measure in the SIP and shifted it to a contingency measure. EPA approved the division on January 10, 2012 (77 FR 1414 (PDF)(4 pp, 156 K). 

On September 20, 2011, Alaska submitted a SIP revision to update Anchorage's CO motor vehicle emissions budget in the Anchorage area using the EPA's Motor Vehicle Emission Simulator (MOVES) model. 

On April 22, 2012, the State submitted a Second 10-Year Limited Maintenance Plan (LMP) for CO for the Anchorage area. The area qualified for an LMP since the second highest 8-hour CO concentration for the Anchorage area during the most recent 8 quarters (2011-2012) was 5.5 ppm, which is below the LMP Option requirement of 7.65 ppm. The EPA approved these SIP revisions on March 3, 2014 (79 FR 11707 (PDF)(5 pp, 228 K).

Source: United States Environmental Protection Agency.

Resources

Maintenance Plan (SIP)

• EPA Approved CO Limited Maintenance Plan (PDF)

Graphs

• Graph of CO trend for Exceedances (PDF)

Memorandums

• Memorandum of Understanding between ADEC & Municipality of Anchorage (PDF 4.5M)

Projects By ADEC

• Projects, Reports, & Inventories

Maps/Monitoring Plans

• CO Maintenance Area Boundary Map (PDF)
• Anchorage Air Monitoring Plan
• Anchorage Air Quality Monitoring Data - CO

Control Measures

• Vehicle Emission - I/M Testing
• Ethanol-Blended Fuels (PDF)

Municipality of Anchorage Website Links

• Air Quality Program
• Air Quality Trends In Anchorage (1980-2010, PDF)