Sewage System | Municipality of North Perth

New Builds and Septic System Modifications

For new construction projects on properties that require a septic system—or when modifying, expanding, or repairing an existing system—a separate sewage system permit is required. This applies to both residential and non-residential properties. Your building permit will not be issued until the septic system permit has been applied for and issued.

Residential Additions or Renovations with a Existing Septic System

If your residential project involves any of the following a septic audit form is required:

An increase in floor area greater than 15%
The addition of a new bedroom
The installation of new plumbing fixtures

You must submit a Septic Audit Form. If the audit determines that the current septic system is insufficient, a new or amended building permit application will be required for either a system expansion or a full replacement.

Non-Residential Additions or Renovations

For non-residential properties, a Septic Audit Form is required when:

There is a change in major occupancy (e.g., converting a retail space to a restaurant)
There is an increase in occupant load

If the audit shows the existing system cannot meet the new demands, a new or updated building permit application will be necessary to expand or replace the septic system.

Permit Application - Forms and Guidelines for Sewage System Permits

Click here to go to our Forms/Documents Page to download any forms listed below.

* signifies additional documents that might be required depending on your project

Application Form

This is part of the Cloud Permit Process and done through the software, no additional document is required when submitting through CloudPermit

Owner Authorization Form

Ensuring the current property owner grants permission to either construct themselves or to have another party, such as a contractor or builder, to apply for and manage a building permit on their behalf.

Septic Package*

This package includes the following components that are required for a sewage system permit application:

a. Property Layout - Ensure clear depiction of required setbacks
b. Designer Information/Schedule 1
c. Schedule 2 - Standard requirements for sewage system designs and installations
d. Schedule 3 - Outlines inspection, maintenance, and operation requirements

Septic Audit Form

A Septic Audit Form is required when:

A residential addition or renovation increases floor area by more than 15%, adds a new bedroom, or includes new plumbing fixtures.
A non-residential addition or renovation involves a change in major occupancy or an increase in occupant load.