DERA School Bus Emissions Program

Riding the school bus is the safest way to get to school. But students exposed to diesel exhaust from school buses can experience adverse health effects. Diesel exhaust contains fine particles which can aggravate asthma and cause lung damage. Children's School Bus Exposure Study conducted by the California Air Resources Board characterizes the range of children's exposures to diesel vehicle-related pollutants and other vehicle pollutants during their commutes to school by diesel school buses.

Maine implements a statewide program to encourage:

  • reducing school bus idling and creating no-idling zones around all school facilities
  • using auxiliary direct fuel-fired heaters
  • using alternative fuels
  • retrofitting buses

Past Grant Awards

  • Bus retrofits: From 2004-2007 the Maine DEP retrofitted over 500 school buses in 30 school districts covering 86 towns with diesel oxidation catalysts and closed crankcase ventilation systems. Maine’s Clean School Bus Program became a national model and earned the distinction of receiving the Environmental Merit Award from EPA New England.
  • Auxiliary heaters: Maine DEP awarded grants for factory installation of auxiliary fuel-fired heaters in more than 120 new school buses.
  • Alternative Fuels:
    • Maine DEP awarded funding under the Diesel Emission Reduction Act (DERA) to help Portland Public Schools purchase ten alternative fuel technology compressed natural gas (CNG) school buses from 2003-2012.
    • Maine DEP awarded funding under DERA to help MSAD #6 purchase six propane school buses from 2009-2010 and the Town of Scarborough purchase 4 propane school buses from 2010-2011

no idle sign

School bus no-idling signs are available. Contact Lynne Cayting

No Idling

A bus can burn approximately one gallon of diesel fuel for each hour it idles. Idling wastes fuel and exposes children and drivers to harmful diesel exhaust. Direct fuel-fired heaters on a timer to warm up the school bus engines and cabins in the morning to avoid idling. Direct fuel-fired heaters can reduce school bus idling by more than half; saving money and reducing emissions.

Please contact Lynne Cayting with any questions at (207) 287-7599 or

Information and Materials