Backflow preventionRegion of Durham, By-law 24-2018
Backflow preventer testing and installation in Oshawa
Spec-Mark Group surveys properties and tests, installs and repairs backflow preventers for industrial, commercial, institutional and multi-residential properties in Oshawa. The Region of Durham runs the program under By-law 24-2018. The City of Oshawa issues the building permit for a new device and publishes its own requirements for it. Spec-Mark Group is on the Region's qualified contractor list, listed under its former name, Spec-Mark Mechanical.
The Durham program in brief
Durham's By-law 24-2018 requires a premise-isolation backflow preventer, tested every year, on any industrial, commercial, institutional or multi-residential water service with a severe or moderate hazard. The cross-connection survey identifies the hazards and is filed through Backflow Solutions Inc. (BSI) within 90 days of the Region's notification. The work the Region orders is completed within 180 days. Every test report is filed within 28 days and a failed device is reported within 24 hours; the Region's 2026 fee schedule sets the report fee at $26.00. The Region of Durham guide covers the full program, including the May 2026 amendment.
The Ontario Building Code's plumbing part (Part 7) and the CSA B64 standards also apply. The municipal by-law adds the program around them: who is surveyed, how often each device is tested, where the report goes and by when.
A permit for a new device in Oshawa
Oshawa publishes its own requirements for this permit. The application goes through the City's online Application Portal under the Plumbing type. It includes the Region's cross-connection survey, the Region's notice to install, the expansion-tank sizing form and the plumber's licence details. Engineered drawings and a Commitment to General Review are required when the backflow service is 2½ inches or larger, or on a fire system of any size. Under Building By-law 33-2009 the 2026 fee is a flat $82 per backflow preventer, with a $160 minimum on any application. An inspection of a device on a fire main carries its own $160 fee. We apply for it as part of an installation.
What we do in Oshawa
We work across Oshawa, including Northwood Business Park and the industrial areas of south and central Oshawa.
- The cross-connection survey the Region's notification asks for.
- The local building permit and the installation where the Region requires a device.
- The annual test of every device, with the report submitted through BSI, a copy to the local municipality, and the report fee paid on your behalf.
- The next due date kept on file, with a courtesy reminder before it; the due date remains the owner's responsibility.
Our certificates are listed on the Qualifications page.
Questions about backflow in Oshawa
Is a backflow preventer required for my property in Oshawa?
Durham's by-law applies to industrial, commercial and institutional properties, and to multi-residential buildings with more than six units. Houses are normally outside the program, but the by-law also applies to any property where a condition may be hazardous to the drinking water system. A premise-isolation device is required where the survey classifies the water service as a severe or moderate hazard. A severe hazard takes a reduced-pressure assembly (RP, also called an RPZ), a moderate one a double check valve assembly (DCVA).
What does backflow compliance cost in Oshawa?
The Region of Durham charges $26.00 for each test report under its 2026 fee schedule, paid online when it is submitted. A survey report has no fee. The City of Oshawa's building permit is a flat $82 per backflow preventer, with a $160 minimum on any application, under its 2026 schedule. An inspection of a device on a fire main carries its own $160 fee. We quote from the notice and the number, size and type of devices.
Is a backwater valve the same as a backflow preventer?
No. A backwater valve is a sewer device that helps protect a basement from sewage backup. A backflow preventer protects the drinking water supply, and it is what the Region of Durham's notice is about.
Who sends the notice in Oshawa, and who issues the permit?
The Region of Durham sends the notification and, after the survey, the notice to install, repair or test. Reports go to the Region through BSI, and the by-law also requires a copy to the local municipality. In Oshawa the building permit comes from the City through its online Application Portal.
The full program is on the Region of Durham page. Also under this program: Pickering, Whitby, Ajax, Clarington, Uxbridge, Scugog, Brock.
Sources
- Region of Durham, Backflow Prevention Program
- Region of Durham, 2026 Fees and Charges, Water and Sanitary Sewer User Rates (PDF)
- Region of Durham, Backflow Prevention By-law 24-2018, office consolidation June 2026 (PDF)
- Backflow Solutions Inc., Durham Region survey form and qualified contractor list
- City of Oshawa, Backflow Device (building permit requirements)
- City of Oshawa, Building By-law 33-2009 as amended by By-law 118-2025, Schedule B (fees effective January 1, 2026, PDF)