Air Quality Requirements
MAG was designated by the governor in 1978 to serve as the Regional Air Quality Planning Agency. Within this role, MAG develops air quality plans required by the Clean Air Act to reduce carbon monoxide, ozone and particulate pollution.
MAG also conducts the air quality conformity analysis on the Regional Transportation Plan and Transportation Improvement Program to ensure that transportation activities do not contribute to air quality violations.
When a region fails to meet federal air quality standards as outlined under the Clean Air Act, it is classified as being in “nonattainment” of the standards.
Air Quality Pollutants
At one time, our region was designated by the Environmental Protection Agency (EPA) to be in nonattainment for three pollutants: carbon monoxide, ozone and PM-10. While significant progress has been made in all areas, particulate pollution remains a major challenge for the region. Here is the current status:
- Carbon Monoxide: There have been no violations of the one-hour carbon monoxide standard since 1984 and the eight-hour standard since 1996. EPA redesignated (April 2005) the Maricopa County nonattainment area as having met the federal air quality standards for carbon monoxide. The EPA also approved the MAG Maintenance Plan, which indicates that the standards would be maintained through 2015. The nonattainment area is now a Maintenance Area. The MAG 2013 Carbon Monoxide Maintenance Plan indicates that the standards would be maintained through 2025.
- One-Hour Ozone: There were no violations of the one-hour ozone standard at any monitor after 1996. EPA redesignated the Maricopa County nonattainment area as having met the federal one-hour ozone standard (June 2005) and the area was reclassified as a Maintenance Area. EPA also approved the MAG Maintenance Plan, which indicates that the standard would be maintained through 2015. However, on June 15, 2005, EPA revoked the one-hour standard.
- Eight-Hour Ozone: EPA designated (June 2004) the eight-hour ozone nonattainment boundary, located mainly in Maricopa County and Apache Junction in Pinal County. The area had a June 2009 attainment date. MAG submitted an Eight-Hour Ozone Plan (2007) that demonstrated attainment of the standard by June 2008. In February 2009, the MAG Eight-Hour Ozone Redesignation Request and Maintenance Plan was submitted to the EPA, which demonstrated that the standard would be maintained through 2025. There have been no violations of the 0.08 parts per million eight-hour standard at air quality monitors since 2004. On June 13, 2012, EPA published a final notice to approve the MAG 2007 Eight-Hour Ozone Plan. On September 17, 2014, EPA published a final notice to approve the MAG 2009 Eight-Hour Ozone Redesignation Request and Maintenance Plan.
In 2008, EPA revised the eight-hour ozone standard to 0.075 parts per million (from 0.08 ppm). On May 21, 2012, EPA published a final rule to designate the Maricopa nonattainment area as a Marginal Area. The boundaries of the nonattainment area were expanded slightly to the west and south to include new power plants. On June 27, 2014, the MAG 2014 Eight-Hour Ozone Plan-Submittal of Marginal Area Requirements for the Maricopa Nonattainment Area was transmitted to EPA. Due to a subsequent court ruling, EPA published a final rule on March 6, 2015 revising the attainment date for Marginal Areas from December 31, 2015 to July 20, 2015.
- PM-10 (Particulate matter that is 10 microns in diameter or less): Currently, the Maricopa County nonattainment area is classified as a Serious Area for PM-10 particulate pollution. The new MAG 2012 Five Percent Plan for PM-10 is designed to meet the requirements of the Clean Air Act and address the technical approvablility issues with the prior 2007 Five Percent Plan identified by the EPA. The plan contains a wide variety of existing control measures and projects that have been implemented to reduce PM-10 and includes a new measure designed to reduce PM-10 during high risk conditions, including high winds. While the 2007 Five Percent Plan was withdrawn to include new information, a wide range of control measures in that plan, which continue to be implemented to reduce PM-10, were resubmitted. The plan demonstrates that the measures will reduce emissions by five percent per year and demonstrates attainment of the PM-10 standard as expeditiously as practicable, which is 2012.
On July 20, 2012, EPA made a completeness finding on the plan, which stopped the sanctions clocks that were related to the withdrawal of the prior 2007 plan. On June 10, 2014, EPA published a final notice to fully approve the MAG 2012 Five Percent Plan for PM-10, effective July 10, 2014.
- PM-2.5 (Particulate matter that is 2.5 microns in diameter or less): The region is in attainment for PM-2.5.
Additional PM-10 Information
More than three exceedances at any one monitor over a three-year period equal a violation.
Sanctions can be imposed for:
- Failure to submit a plan.
- Failure to implement any plan requirement.
- Failure to make any required submission.
- EPA disapproval of the plan.
Conformity Freeze – Occurs 30 to 90 days after final disapproval of plan (without a protective finding) is published in the Federal Register.
- Only projects in the first four years of the conforming Transportation Improvement Program (TIP) and Regional Transportation Plan (RTP) can proceed.
- No new TIPs, RTPs or projects can proceed until a Five Percent Plan revision is submitted that fulfills the Clean Air Act requirements, EPA finds the conformity budget adequate or approves the submission, and conformity to the plan revision is determined.
Clean Air Act sanctions would be imposed if the problem is not corrected within:
- 18 months from the disapproval action. Sanctions include:
- Tighter controls on major industries (2:1 offsets in emissions).
- 24 months from the disapproval action. Sanctions include:
- Loss of federal highway funds equating to tens of thousands of jobs. In addition a federal implementation plan will be imposed.
Imposition of highway sanctions may trigger a conformity lapse.
- Major projects in the MAG Transportation Improvement Program could not proceed.
How Can the Public Help?
Remember, the dust we raise is the dust we breathe. Dust in the air is a problem we can solve. Here are some simple steps people can take to reduce dust pollution:
Don’t drive on dirt:
- Don’t take short cuts across vacant lots.
- Don’t drive on dirt shoulders.
- Don’t park on dirt.
- Drive slowly on unpaved roads.
Avoid using leaf blowers and gas-powered lawn and garden equipment.
Reduce fireplace and wood stove use, and don’t use your wood-burning fireplace on no-burn days.
Ride ATVs and other off-road vehicles outside the Valley’s nonattainment area. Off-road vehicles are prohibited in many areas, especially on high pollution advisory days. Drivers should check with the appropriate agency before driving, riding or parking on any land.