Protecting Public Health and the Environment.

Clean Air Zone Program for Schools

DEQ's Anti-Idling Program

The Clean Air Zone Program is designed to encourage Idahoans to turn off their engines instead of idling. The program began in 2004 with a campaign aimed at encouraging school bus drivers and others not to idle on school grounds. To date, more than 300 Idaho schools and child care facilities have voluntarily joined the program.

In 2006, the program expanded to discourage vehicle idling at community facilities where idling is common, such as airports, libraries, parks, sports areas, and universities. To date, more than 30 Idaho communities have joined the program.

Subsequent efforts have focused on encouraging businesses to join the Clean Air Zone program. Businesses with delivery vans or truck fleets are great candidates for participation in the program, as are businesses with loading docks or drive-through lanes or parking lots where vendors or customers often sit and idle.

The goals of Clean Air Zone for schools are to:

  • Provide a healthier environment for Idaho's school-children by reducing
    emissions from diesel-powered school buses and other vehicles;
  • Improve air quality in and around school buildings and throughout local
    communities; and
  • Assist school districts in obtaining funding to use cleaner fuels, replace existing buses with cleaner models, and/or retrofit buses with advanced emission control technologies.

Health Impacts of Diesel Exhaust

Diesel exhaust aggravates asthma, emphysema, and bronchitis, according to the U.S. EPA, and exacerbates allergies. Based on human exposure studies as well as lab data, EPA has concluded that diesel is a probable carcinogen.

While dropping off or picking students up from school and waiting, idling buses and vehicles emit fine particulate matter and other air pollutants, which can impact air quality and public health. Bus idling and bus queuing can further increase the concentrations of particulates both inside school buses and inside nearby buildings. Although breathing diesel exhaust may not measurably impair lung function in adults, studies show that particulate pollution can impair the development of lungs in children. Fortunately, schools can take several steps to reduce diesel exhaust from school buses.

Things Your School Can Do

Reduce Exposure

  • Establish guidelines to reduce or eliminate idling of buses and other vehicles.
  • Park buses away from children's gathering places and building intake vents.
  • Inform parents and other vehicle users of no-idling policies in front of schools, especially during periods when large numbers of children are present (pickup and drop-off times).
  • Create a clean air zone around your school to comprehensively address children's exposure to air pollution.

Use Alternative Fuels

Using cleaner fuels is one way existing buses can be upgraded (or "retrofitted") to pollute less. Possible alternative fuel options include:

  • Biodiesel Fuels: Biodiesel, a mixture of diesel fuel with soybean or vegetable oil-based products, can reduce fine particulate emissions by up to 10%, and also may reduce the toxicity of diesel emissions. A standard diesel engine can operate on biodiesel mixtures of up to 20% without physical modifications. The incremental cost of 20% biodiesel typically ranges from 12-20 cents per gallon.
  • Ultra-Low Sulfur Diesel: ULSD has significantly less sulfur content, which results in up to 10% reductions of fine particulates, and can be used in any diesel vehicle. The additional cost of ULSD ranges from 8-20 cents per gallon.

Take Advantage of Bus Retrofit and Purchase Programs

Across the country, local school districts have purchased more than 2,600 clean alternative fuel buses over the past few years. With the increase in federal funding under the Clean School Bus Program, the opportunity has never been better for Idaho schools to participate in this nationwide program. DEQ is committed to helping Idaho schools in finding and applying for funds to:

  • retrofit buses with new technologies
  • replace old buses with new cleaner buses
  • repair and maintain existing buses to run safe and clean
  • Participate in Idaho's School Bus Diesel Retrofit Program: Idaho's Diesel Retrofit Program is a statewide effort to retrofit school buses with new technologies designed to reduce emissions. For information or to join, contact G. Michael Brown at (208) 373-0232 or

Join the Clean Air Zone Program

Take a pledge to "get into the zone." Participating schools receive a Clean Air Zone Toolkit (download below), technical and policy assistance, and information on funding opportunities.

Clean Air Zone Toolkit for Schools

The Clean Air Zone Toolkit is comprised of the following informational materials which may be downloaded in PDF format: