Septic Systems

In areas of the Town of Caledon without sanitary sewers, sewage disposal is the responsibility of each property owner.

A properly constructed and maintained on-site sewage disposal system will work effectively and safely for many years. If the system is not set up properly or maintained, it can become a health concern, damage the environment, and cost a lot to repair.

Adding or changing sewage disposal system

New developments that will use on-site sewage disposal, or if you're making changes on your property that may impact an on-site sewage disposal system, you will require a building permit. Contact us to request a building permit application.  

Approval process

The Building Code Act and the Ontario Building Code set the standards for on-site sewage disposal systems that discharge 10,000 litres and less. The Building Code requires that you have a completed sewage system before occupying a building.

Sizing the system

After determining the daily design flow, a geotechnical engineer will need to complete a soils analysis, which shows the percolation capacity of the soil.

Using the daily design flow, soils analysis, and the requirements listed in the Ontario Building Code, a design can be completed.

Submitting the design

Your design must include:

  • Two copies of a site plan (scaled map) that shows the sewage system, all structures on the property, wells, watercourses, property lines, etc. and measurements to those features
  • The soils analysis including the percolation capacity
  • A completed Building Application Form and Certificate of Approval for a Sewage System.

The property owner, or an authorized agent acting on behalf of the owner, can complete the application form.

All contractors installing or designing on-site sewage disposal systems in Ontario must be licensed with the Ministry of Municipal Affairs and Housing. In some cases, a professional consulting engineer might be needed to design the sewage system.


Starting installation

We issue a certificate of approval if the design is acceptable, which allows construction of the sewage system. If the sewage system will service a new building or building addition, you can now apply for a building permit.


Before covering any part of a sewage system, a Town of Caledon Building Inspector must complete an inspection and give approval.

Book an inspection

For example, a Class 4 system would require an inspection of:

  • sewage system area
  • contact area as used in a raised system
  • septic tank(s)
  • pump chamber, pumps, and pump controls/alarms
  • leaching bed piping
  • final grading inspection

Care and maintenance of a sewage system

With care and maintenance, a sewage system can last for many years. There are, however, some things which you, the sewage system owner, should be aware of that will help the system to function.

Have a problem with your system?

You must notify us right away if you're having problems with your on-site sewage system. This can include sewage waste discharging from the leaching bed onto the ground surface. You must have a licensed on-site sewage system installer repair your system.

Inspect your septic tank

You should have your septic tank inspected every two years. The tank should be pumped out every four years to prevent the buildup of sludge (settled solids) and scum (floatables), which can create issues.

Leaching beds

If the septic tank is working and maintained properly, only liquid waste should be discharged to the leaching bed system.

Make sure that the area over your leaching bed is covered with grass, well ventilated, and gets enough sunlight. Never allow vehicle traffic over a leaching bed. Vehicles can cause soil compaction and damage the piping.


When landscaping, never add soil to the leaching bed. Never place structures such as patios, sundecks, and tool sheds over your leaching bed.

Vegetable gardens and any root crops are not recommended over a leaching bed. Never plant trees and shrubs close to the leaching bed as roots can disrupt piping.

Water usage

Keep water usage to a minimum as using too much water can impact the disposal of liquid sewage and could flush solids from the septic tank into the leaching bed.

Never install an automatic irrigation system on or around leaching beds. You should also divert any surface water away from leaching beds.

Household drain solvents, cleaners, or disinfectants

While using household drain solvents, cleaners, or disinfectants moderately shouldn't interfere with the sewage disposal system, using too much may cause problems.

Never pour chemicals such as paint thinners, pesticides, and herbicides down the drain as they contaminate ground water.

Never enter a septic tank

Never enter a septic tank. Noxious gases remain in the tank after the top is removed. They have lead to the death to both the original victim and those who attempted to rescue them.