General Information About On-site Systems in Ontario

On-site wastewater treatment systems are very popular in rural and unserviced parts of Ontario. The following points provide some general information about on-site systems in Ontario.

  • Normally rural homes, sub-divisions, and cottages outside of town or city boundaries rely on on-site treatment and dispersal for their wastewater. This means they are NOT connected to a municipal sewer and wastewater treatment plant.
  • On-site systems treat wastewater that is generated in the home right there on the lot, unlike centralized systems that use sewers to convey the waste away from homes to a wastewater treatment plant.
  • On-site systems can be an effective method of treating wastewater in many cases due to the high cost of building and maintaining wastewater treatment plants.
  • In Ontario there are approximately 1.2 million On-site systems, and this number is increasing at a rate of 25,000 systems each year.
  • The most common type of On-site treatment system is the conventional septic system & variations of it.
  • On-site systems with a daily design flow of less than 10,000 L/day are regulated by Part 8 of the Ontario Building Code. This regulation is generally delivered by your local building department, or in some cases by the local Health Unit or Conservation Authority.
  • On-site systems almost always use subsurface dispersal methods. Surface water discharge systems must get special approval from the Ministry of the Environment, no matter what the size.
  • On-site systems must be designed and installed by a licensed person to complete the work. Individuals are licensed by the Ministry of Municipal Housing & Affairs.