Sewage Systems

Sewage systems are a necessary, and very important part of health and safety for your home or for other buildings.

Municipal sewage systems are a complex system requiring engineers to design and experts to maintain.

For the average homeowner visiting this page, we will discuss individual Septic systems serving a single building lot.

 Installing your Septic System

Although a homeowner may design and install their own septic system, this is something that is best left to professionals.

Even though a septic system may look like just a tank and some pipe buried in the ground, it is really a carefully designed system of components that must work together. If not designed and installed correctly, it will not function properly or it will fail prematurely.

When a Septic system fails, it is a serious health hazard and can be very expensive to fix or replace.
To find licensed designers and contractors, you may start by using local directories or contacts.
Another resource is the Ontario Onsite Wastewater Association (OOWA) Directory of Professionals. 

 When You Need a Permit
 There are three cases where a permit is, or may be required:
  • A new septic system.
  • Repairing or adding to an existing septic system.
  • Making changes to a building such as additions, renovations, construction that affects a sewage system, or change of use. All of these are triggers for an Existing Septic System Review and a possible permit.
Existing Septic Systems Review

One of the things that can cause septic failure, is if it is used beyond the designed capacity.

Therefore, it is important to always inquire when you are upgrading your home in some way, to ensure you do not overload your system.
If you are making changes to a building such as additions, renovations, construction that affects a sewage system, or change of use, the following are triggers for a review and a possible permit:

  • The changes to the building have resulted in an increase in occupant load.
  • The number of bedrooms in a dwelling unit has increased.
  • Proposed construction exceeds 15% of the finished (gross) area of the dwelling or dwelling unit, or if finished (gross) area exceeds 200 square metres.
  • Additional (new) plumbing fixtures are added to the dwelling or dwelling unit.

Please submit an Existing Sewage System Review form if any of the above triggers are true.

Submit using Cloudpermit. The instructions for doing this are in the next heading below “Septic System Application for a Permit”.

We will review your existing system application which will include an interior inspection of the existing septic tank. The existing leaching bed may also need to be exposed for further inspection. This will ensure that your existing system is in good working order and does not need to be replaced.

Based on the review, we will either issue a letter stating that your existing septic system has the capacity to handle the added load, or we will ask you to apply for a permit to resize or replace.
If you require a permit, you will be able to use the same permit application you have already submitted for the review. You will be informed of any further documents you will need to submit.

 Septic System Application for a Permit

A sewage system building permit is required to install, repair or replace any part of a septic system.

Either the owner, the designer, or the installer may submit the application.

The application process is completed using the Cloudpermit online permitting system.

If you are not familiar with Cloudpermit, please go to our Cloudpermit page for instructions on how to use it and set up your account.

Do not use Cloudpermit without first reading all the instructions. 

 Required Documents

 The following documents will be required for your application submission:

 Forms Built into Cloudpermit in the “Application Forms” Section.
  • Permit Application: Completed and signed by the applicant.
  • Schedule 1: Designers Information completed and signed by a qualified Designer.
  • Schedule 2: Septic Systems Installers Information signed by a qualified Installer.
 Required Forms to Submit in the “Attachments” Section.

The following required forms must be submitted.  

  • Architectural plans. 
  • Site grading plan. (as required)
  • Septic Layout Plan – Showing septic system and all distances from lot lines, all buildings, well, high water mark and overhead power lines.
  • Class 4 and 5 Systems - These forms are combined into one document. (Please Note: this is a fillable form. You must save it to your device before adding to Cloudpermit or the filled fields may be blank.)
    • 3A: Site Evaluation Form.
    • 4A: Design Criteria.
    • 5A: Proposal to Construct.
    • 6A: Drawing A - Buried or Raised Leaching Bed Absorption Trench. (as Applicable)
    • 7A: Drawing B – Buried or Raised Filter Bed. (as Applicable)
    • Authorized Agent Form – required if anyone other than the owner submits the application.
  • Class 2 and 3 Systems - These forms are combined into one document. (Please Note: this is a fillable form. You must save it to your device before adding to Cloudpermit or the filled fields may be blank.
    • 3B: Site Evaluation Form.
    • 4B: Design Criteria.
    • 5B: Proposal to Construct.
    • Authorized Agent Form – required if anyone other than the owner submits the application.
  • Existing Sewage System - These forms are combined into one document. (Please Note: this is a fillable form. You must save it to your device before adding to Cloudpermit or the filled fields may be blank.)
    • Existing Sewage System Review form.
    • Authorized Agent Form – required if anyone other than the owner submits the application.
Additional Required Approvals Based on Property Location, Site Conditions or Type of Occupancy
  • Conservation Authority, Source Water Protection, MNR, MTO, or MECP approvals. (where applicable)
  • A separate calculation page if the system includes non-residential occupancies.
  • Property Survey (upon request)
  • Site Plan development agreement. (if required by Planning Services)
  • Building Materials Evaluation Commission (BMEC) or Can/BNQ “Onsite Residential Wastewater Treatment Technologies” approvals. (if applicable)


Septic System Fees

A non-refundable Administration Fee of $100.00 applies to all permits.
 Class 4 Sewage System <= 4500 litres/day
Class 4 Sewage System > 4500 litres/day and <= 10,000 litres/day
Class 4 Sewage System Tank Replacement Only
Class 5 Sewage System (Holding Tank)
Class 3 (Cesspool) or Class 2 (Greywater)
Trench Bed Repair or Extension of 16 m or less
Filter Bed Repair, Replacement or Extension of 6 m sq. or less
Change of use - Existing System Review
Mandatory Maintenance Inspection
Inspection of Sewage Systems (Source Water Protection Areas)
Discretionary Maintenance Inspections

Basic Inspections

Advanced Inspections

 Resources for Designers and Installers
Here are some excellent resources for Professionals.
 Resources for Property Owners

Here are some excellent resources for a homeowner to help you understand and maintain your sewage system enabling you to have many years of trouble-free sewage treatment.

   Classes of sewage systems information pages. 

 Class 1 Sewage Systems (privies, chemical or composting toilets etc.)
 Information Sheet
Class 2 Sewage Systems (leaching pit)
Class 3 Sewage System (Cesspool)
Class 4 Sewage System (Septic tank and leaching bed)
Class 5 Sewage System (Holding Tanks)


 Additional Resources

There are three kinds of inspections. 

They are Permit inspections, Treatment Unit inspections, and Mandatory inspections. 

 Permit Inspections

These inspections are part of the permit process.

When you have a repair, replacement or new Septic System, these inspections will be outlined on your copy of the permit.

When using Cloudpermit, requesting an inspection is as simple as clicking on the required inspection and following the prompts.

  • Site Inspection includes;
    • Two test holes need to be dug in the location of the proposed leaching bed.
    • The test holes require a minimum depth of 1.5 metres, or to depth of water table, or bedrock.
    • Proposed home location must be staked.
    • All property lines must be identified.
    • Neighbouring well locations and depth of watertight casing.
    • Site features identified (ex. ditches, run off, swales, etc.)
  • Base Cut Inspection includes;
    • Entire bed area excavated.
  • Final Inspection includes;
    • Tank stamp exposed.
    • Header and Footer / ends of runs exposed.
    • Subsurface detection in place.
    • Weigh slips provided, for filter media and Type A Beds or BMEC purposes.
  • Grading / Backfill Inspection includes;
    • Top soil, sodded or seeded. 
Treatment Unit Inspections

If your septic system incorporates a treatment unit there are regular mandatory inspections that the owner is required to perform. A maintenance agreement is required with the person operating the treatment unit.


Sampling reports must be submitted to the Chief Building Official. Reports must be added to the Attachments section of your sewage system permit in Cloudpermit.

Mandatory Inspections

In the mandatory program, under Part IV (4) of the Clean Water Act, the principal authority is required to conduct inspections of on-site sewage systems located in “vulnerable areas” as outlined in source protection plans. The Otonabee Region Conservation Authority has identified, mapped and geocoded these vulnerable areas in its source protection plans.

These inspections are required every 5 years.

A review of the existing sewage system will be made once the questionnaire has been submitted. The size and location of the existing sewage system will be assessed to determine if the sewage system is a threat to the source water supply.


  • This addresses the dwelling and its interior components such as bedrooms, fixture units and finished area.
  • Included is the location of the sewage system, tank, and leaching bed.
  • Site Plan showing well, house, driveway, accessory structures, pool etc.
  • The lids of the septic tank must be uncovered for inspection purposes.
  • Possibly uncover a portion of leaching bed when directed to do so.

Request for Sewage System Installation Report

If you would like information about an existing sewage system, please submit the Sewage System Installation Report Request form.