Air quality is important to Southeast Michigan's quality of life. As the designated lead local air-quality planning agency under the federal Clean Air Act, SEMCOG works with the Michigan Department of Environmental Quality (MDEQ) to develop plans and programs that comply with federal air quality standards. Efforts are geared toward attaining and maintaining air quality standards in the most cost-effective manner.

Ensuring that Transportation and Air Quality Plans Align

The Clean Air Act requires that SEMCOG’s long-range transportation plan and Transportation Improvement Program conform to the requirements and pollution budgets in the State Implementation Plan. SEMCOG is responsible for ensuring this conformity is demonstrated. Download a copy of SEMCOG’s latest conformity analysis (pdf, 242KB).

Ozone Action – Promoting Public Involvement in Improving Air Quality

Through the Ozone Action Day program, SEMCOG helps everyone in the region understand that they have a role to play in keeping the air clean in Southeast Michigan. Ozone Action Days are called on hot, sunny days when heat and pollution emissions are expected to combine and create elevated concentrations of ground-level ozone.

Quantifying Pollution from Cars and Trucks

In support of transportation and air quality planning activities, SEMCOG inventories emissions from on-road mobile sources (cars and trucks). Data from SEMCOG’s travel forecasting model, as well as the U.S. Environmental Protection Agency's (EPA) MOVES model, are used in this process.

Pinpointing Air Quality Problems and Identifying Cost-Effective Solutions

Under the federal Clean Air Act, each state must have a State Implementation Plan (SIP), which identifies how it will attain and/or maintain National Ambient Air Quality Standards (NAAQS). SEMCOG collaborates with the Michigan Department of Environmental Quality (MDEQ) to prepare and/or update the SIP for Southeast Michigan. Examples of this work include evaluating the effectiveness of potential control measures, developing air quality attainment strategies, and coordinating Southeast Michigan’s air quality technical advisory group, which provides critical expertise on the science that drives our air quality.

Specific Air Quality Reports

As part of SEMCOG’s effort to attain and maintain the national fine particulate (PM2.5) standards, SEMCOG sponsored an extensive study to identify the characteristics of high-PM2.5 days in Southeast Michigan. The results of this study are documented in the 2008 report, A Conceptual Model for Ambient Fine Particulate Matter over Southeast Michigan: High Concentration Days (pdf, 3.2MB), which was prepared for SEMCOG by Dr. Jay Turner of Washington University in St. Louis. This information formed the basis for the pollution control strategy that was successfully implemented in the region. As a result, Southeast Michigan has been in attainment of both the annual and 24-hour PM2.5 standards since 2009.

In summer 2007, SEMCOG conducted a pilot program aimed at reducing emissions from high-polluting vehicles using remote sensing technology and increased public awareness. Read about the findings of this program in the SEMCOG report, Passenger Vehicles and Air Pollution: A Profile of Southeast Michigan’s Fleet.

Developing Regional Solutions
SEMCOG is a regional planning partnership of governmental units serving 4.7 million people in the seven-county region of Southeast Michigan striving to enhance the region's quality of life.