Ontario Building Code - Sewage System Definitions

Sewage system means

(a) a chemical toilet, an incinerating toilet, a earth pit privy, a pail privy, a privy vault and a recirculating toilet, a self-contained portable toilet and all forms of privy including a portable privy, an composting toilet system,
(b) a greywater system,
(c) a cesspool,
(d) a leaching bed system, or
(e) a system which requires or uses a holding tank for the retention of hauled sewage at the site where it is produced prior to its collection by a hauled sewage system,
where these
(f) have a design capacity of 10,000 Litres per day or less,
(g) have, in total, a design capacity of 10,000 Litres per day or less where more than one of these is located on a lot or parcel of land, and
(h) are located wholly within the boundaries of the lot or parcel of land on which is located the building which they serve.

Septic tank means a watertight vault in which sanitary sewage is collected for the purpose of removing scum, grease and solids from the liquid without the addition of air and where solids settling and anaerobic digestion of the sanitary sewage takes place.

Treatment unit means a device which when designed, installed and operated in accordance with its design specifications provides a specific degree of sanitary sewage treatment reducing the contaminant load from that of sanitary sewage to given effluent quality.

 (2.1) Sewage Systems
In addition to the criteria set out in subsection (2), a sewage system is unsafe if it is not maintained or operated in accordance with this Act and the building code. 1997, c. 30, Sched. B, s. 10(1).

Leaching bed means an absorption system constructed as absorption trenches or as a filter bed, located wholly in filter media that is contained between the surface to ground or raised or partly raised above ground as required by local conditions, to which effluent from a treatment unit is applied for treatment and disposal and that is composed of,

(a) the soil (as defined in Part 8), leaching bed fill or other which the sanitary sewage is applied and the bottom of the bed,
(b) the distribution pipe and the stone or gravel layer in which such pipe is located, and
(c) the backfill above the distribution pipe, including the topsoil and sodding or other anti-erosion measure, and the side slopes of any portion elevated above the natural ground elevation.


Leaching bed fill means unconsolidated material suitable for the construction of a leaching bed placed in the area of the leaching bed in order to obtain the required unsaturated zone below the distribution pipes, and the required lateral extent such that the effluent is absorbed.


Private sewage disposal system means a sewage system or a sewage works which is not owned and operated by the Crown, a municipality or an organisation acceptable to the Director responsible for issuing a Certificate of Approval under the Private sewage disposal system means a sewage system or a Ontario Water Resources Act.

Sewage system maintenance

Protect your investment and the environment, take care of your septic system. For a longer, trouble free operation, you have to watch what gets flushed down the drain.

How an on-site sewage disposal system operates

A typical septic system consists of two major components, the tank and the bed. Septic tanks are constructed out of concrete or polyethylene. The tank is separated into two compartments with a baffle inside. The purpose of the tank is to separate the liquids from the solids, and to begin breaking down the contaminants. The solids settle to the bottom, scum floats to the top and the liquid effluent migrates past the baffle to the second compartment. This process occurs anaerobically, (without oxygen), so the tank needs to be sealed.

After leaving the septic tank, the effluent flows to the bed area through the header. The leaching bed consists of perforated pipes, in the ground which distribute the effluent evenly over the natural soil or more commonly now, imported fill. The bed area further treats the effluent aerobically, bacteria which require oxygen, digest and remove the impurities; organic chemicals, viruses, suspended solids etc.. The filtered wastewater then aspirates and evaporates into the air above the bed or leaches into the natural soil and ultimately into the groundwater.

  • Reduce the amount of water and wastewater entering the septic system. This can be accomplished by installing low-flush toilets, water saving fixtures, doing only full loads of dishes or laundry. Fix leaking taps, less water in equals less water out.
  • Pump out the tank every 3 years, and have the tank inspected. 75% of the system failures are traced back to solids clogging the tank and bed
  • Maintain the area over the bed, keep the grass cut. Keep trees away, the roots will enter and clog up the pipes.
  • Use low sudsing, low phosphate detergents. Biodegradable detergents, with washing soda ingredients are recommended. Fabric softner dryer sheets are preferred over liquid softners in the wash.
  • Use recommended cleaning products which are non-chlorine, biodegradable, non-toxic and non-corrosive.
  • Have an effluent filter installed at the outlet of the tank, to reduce the amount of suspended solids entering the bed area.
  • Control water runoff from roofs, driveways and yards, grade away from the leaching bed area.
  • do not do laundry all in one day each week, the large quantities of soapy water agitate the solids in the tank and dilute the beneficial microbes at work 
  • do not use the bed area as a parking lot or skating rink, the bed requires air to function properly. Compacting and/or freezing the soils will reduce the lifespan of your bed. 
  • do not dispose grease, fats and oils into the system, they do not break down and tend to clog the weepers. 
  • do not dump pesticides, herbicides, paints, automobile fluids, household chemicals, home brewery wastes, strong medicines, antibiotics or any other toxins into the system, they kill the active bacteria. 
  • do not drain furnace condensate discharges and water softner backwashes into the plumbing system. Instal a dry well.

On-site sewage systems

On-Site Sewage Systems are regulated by the Municipality under the Ontario Building Code Act.

It is a requirement that on-site sewage systems be designed and installed by licensed professionals. The Municipality issues permits and inspects all sewage systems in the Township, with a daily design flow of less than 10,000 liters per day.

The following are general code requirements for the design of an onsite sewage system;

  • 3 meters (10feet) from property lines
  • tank to be a minimum 1.5 meters (6feet) from buildings
  • the bed area to be a minimum 5 meters (17feet) from buildings
  • bed area to be a minimum 15 meters (50feet) from a drilled well or a minimum 30 meters (100feet) from a dug well

Apply for a permit here