• The Northeast States for Coordinated Air Use Management works with eight Northeastern states to collect information and establish uniformity in air pollution regulations. The agency note says that older outdoor wood burning boilers put out 20 times more pollution than newer model boilers, and emit as much particulate matter as 50 diesel trucks. New Vermont regulations put into effect in 2010 reduce the smoke to acceptable levels.
  
  

Basic Pollution Levels

• State law enacted in 2010 mandates any outdoor wood-burning boiler sold, installed or distributed in Vermont must give off no more than 0.32 pounds of particulate matter per million BTUs of heat output. The current law is Phase II of Vermont's outdoor wood-burning boiler regulations. Phase I began in April 2007 with a requirement that boilers conform to a limit of 0.44 pounds per million BTUs of heat output. Two types of boilers are exempt from Phase II regulations. According to the Vermont State Agency of Natural Resources (ANR) Environmental Protection Regulations, boilers that burn pellet-type fuels "with metered fuel and air feed and controlled combustion engineering" sold or distributed before March 31, 2010 are exempt. Any boiler that used solely for heating homes or water for residential use is also exempt.
  
  

The Basic Requirements

• Phase I and Phase II regulations require different setbacks from occupied buildings. A Phase I compliant boiler must be more than 200 feet away from a residence that they do not own. Phase II boilers have more restrictive rules. A Phase II boiler cannot be located closer than 100 feet from any residence, school or health care facility.
  
  

Modern Fuels and their Effectiveness

• Vermont environmental protection regulations require only certified fuels be used in outdoor wood-burning boilers. It allows untreated natural wood, wood pellets made from untreated natural wood or biomass fuels. Regulations also permit the use of home-heating oil, natural gas or propane when used as a starter or supplemental fuel for dual-fired boilers. According the Vermont State Air Pollution Control Division, compliant boilers are so efficient that they burn two cords of wood to produce the same heat that non-compliant boilers need three cords to match.
  
  

Older Boilers are Still Allowed

• Many citizens in Vermont own older outdoor wood-burning boilers that are non-compliant. State laws allows use of non-compliant boilers if they sit more than 200 feet from any residential building, the owner of the boiler doesn't own the residential buildings, the smokestack is higher than the surrounding buildings and no one complains.