Plumbing and Septic Systems

Northumberland County reviews plans, issues permits and performs inspections for septic systems in all of our member municipalities except the Municipality of Trent Hills. We also work with municipalities to review plans and perform inspections for plumbing in all new buildings, building renovations and additions.

When do I need a plumbing or septic system permit?

A permit is your legal right to build. Make sure you have a permit before you start work.

Work started without a permit can lead to the work having to be uncovered/exposed, higher permit cost or legal action.

You may need to obtain a permit if you are:

  • Building a new building that has plumbing
  • Building an addition that has plumbing
  • Changing the use of an existing building
  • Taking out all or part of a plumbing or septic system
  • Finishing plumbing in a basement or room
  • Changing a room to a bedroom
  • Installing or changing a plumbing system
  • Installing, changing or fixing a private septic system
  • Installing a deck
  • Installing a kitchen or bathroom cupboard with plumbing
  • Installing a lawn sprinkler or soaker system
  • Installing a pylon, roof, billboard or fascia sign with plumbing
  • Installing a commercial or industrial equipment with plumbing
  • Installing a fountain with plumbing
  • Installing or changing a backflow preventer
  • Installing a municipal water service
  • Installing a fire main or hydrant
  • Installing a sanitary or storm drain outside
  • Installing or changing a fire sprinkler system
  • Installing a stand pipe system
  • Installing a glycol system

You do not need a permit for:

  • Minor repairs to a plumbing or septic system
  • Installing a kitchen or bathroom cupboard with no plumbing
  • Changing existing plumbing fixtures in the same location
  • Installing a Class 1 septic system

How do I apply for a plumbing permit?

Please fill out one of our plumbing applications and send it to your local municipality:

For a paper copy of the application, please visit your local municipality's office.


You can pay for plumbing permits at your local municipality – usually as part of their building permit fee.

How do I apply for a septic system permit?

Please fill out our Septic System Permit Application and bring it to our office at 600 William Street in Cobourg.

Fees and payment

Septic system permit: $875

Tank replacement: $450

We accept payment by cheque, debit and credit card. Visit us at 600 William Street in Cobourg to pay in person.

Learn about septic systems

View the SepticSmart! booklet to learn more about your home's septic system.

When do I need a plumbing or septic system inspection?

All new construction of plumbing and sewage systems in Northumberland County (excluding the Municipality of Trent Hills) are subject to inspection by County Plumbing and Sewage System Officials.

Plumbing inspections

Please provide two business days' notice for substantial completion of:

  • Site servicing (outside services)
    • Outside water services, sanitary and storm sewer connections prior to backfilling
    • Testing is required for all industrial, commercial, institutional and multi-residential unit and may be requested by the inspector for any other occupancy type
  • Site servicing (domestic supply)
    • Includes domestic water and fire service mains 3” and larger
    • Testing and sampling is required on all installations and the fire main must be filled using a backflow protected water supply
    • The backflow prevent must be tested prior to use and the test report submitted
  • Under slab
    • Includes interior underground storm and sanitary drains prior to backfilling
    • Testing is required for all industrial, commercial, institutional and multi-residential units and may be requested by the inspector for any other occupancy type
  • Rough-in above ground
    • Includes rough-in of drainage, waste, vents (DWV) and water pipe systems
    • Testing is required for all industrial, commercial, institutional and multi-residential units and may be requested by the inspector for any other occupancy type
  • Final
    • Includes finalizing plumbing systems, fixtures and appliances
    • Final testing is required for all prefabricated houses or at the discretion of the inspector

Septic system inspections

Please provide four business days' notice for the substantial completion of the:

  • Test pit
    • Required for all sewage systems prior to permit issuance
    • The application for the permit must be submitted and complete
  • Readiness to construct the sewage system
    • To provide the inspector the ability to attend the site to discuss with the installer the installation and review the base cut for scarification
  • Final
    • Substantial completion of the installation before the commencement of backfilling

How to arrange an inspection

Call 905-372-1929 or email us.

In your request, please include:

  • Your name
  • Permit number
  • Property address
  • Type of inspection
  • Preferred inspection date (minimum of two business days' notice)

Adding to your septic system

You must apply for a Sewage Disposal System Review for any building additions, renovations or new buildings that you will be adding to your septic system. You will also need a review if your local municipal building department asks you to get our comments for the septic system.

Please note: In your application for a review, you should include a copy of the septic system permit or installation record issued when your septic system was installed. If you do not have your permit or installation record, you will need to request a search of our files.



Search for a septic system permit

Please fill out the Sewage System Search Request Form if you need us to search our files for your septic system permit.

Please note:

  • We do not have records of septic system permits prior to 1985
  • We only have records for properties that we have received an application for
  • Only the current property owner or an authorized person can request a sewage system permit search



What if there is no septic system permit?

You will need to contact an engineer or a licensed sewage system installer to diagram the location, size and type of sewage system on your property. The diagram should include the location of the leaching bed (if applicable) as well as the distances from the property boundary, wells, water features (creeks, rivers, ponds, lakes) and any buildings.