Backflow Prevention Program

The Backflow Prevention Program's purpose is to prevent the backflow of potentially contaminated water from buildings considered severe and moderate hazard risks to the City's drinking water system. This is accomplished by administering a program that identifies affected properties, requires the installation of premise isolation backflow devices and ensures the continued safe function of the devices by overseeing annual testing prescribed under by-law requirement. The program supports compliance with the highest industry drinking water protection standards to ensure public safety and the long-term safety of our shared water resource.

What is backflow?

Typically, drinking water flows in one direction, from the City’s distribution system into a property’s private water system. Water will always travel from higher pressure zone to lower pressure zone. Backflow is the undesired reversal of water flow from a private buildings water system to the City's distribution system, due to reduced water pressure. This reversal or backflow can cause contaminants to enter the drinking water distribution system.

The program's purpose is to prevent the backflow of potentially contaminated water from buildings considered severe and moderate hazard risks to the City's drinking water system.

There are several ways to mitigate the potential for backflow:

• provide a physical separation between drinking and non-drinking water systems
• install backflow prevention devices and assemblies
  • Note: The choice depends on the health hazard of the actual or potential cross-connection and the plumbing hydraulics using a risk based approach.
• maintain positive pressures in the distribution system
• implement backflow prevention programs

Backflow preventers vs. Backwater valves

A backflow preventer is installed on the drinking water service. A backwater valve is installed on the wastewater / sewer service. For more information on backwater valves contact the Residential Protective Plumbing Program.

Causes of backflow

Backflow can occur due to back siphonage or back pressure.

• Back pressure occurs when pressure in a building water system is greater than pressure in the City’s water supply system. This can result in water from the building water system forcing its way into the City’s distribution system. Back pressure may be caused by pumps, elevated tanks, temperature increases in boiler systems, and other local pressure events.
• Back siphonage occurs when pressure in the City’s water supply system is lower than pressure in a building water system. This reversal of pressure can pull contaminated water from the private water system into the City’s distribution system. Back siphonage may be caused by nearby a large consumption of water from fire hydrants or water main breaks.

Methods for Backflow Prevention

Water distribution systems - due to their size, complexity and variety of users - are often exposed to potential health risks. Sources of such health risks include cross-connections and backflow. Implementing a backflow prevention program is one way in which a drinking water system owner can minimize water quality degradation from a source connected to the distribution system.

There are several ways to mitigate the potential for backflow:

• provide a physical separation between drinking and non-drinking water systems
• install backflow prevention devices and assemblies
• maintain positive pressures in the distribution system
• implement backflow prevention programs

Note: The choice depends on the health hazard of the actual or potential cross-connection and the plumbing hydraulics using a risk based approach.

Three primary methods (individual [point of use], zone/area, and premise) are available to protect the drinking water supply. The method used is dependent upon the degree of the hazard. Through the incorporation of the available protection methods the property owner is able to implement a multi-barrier approach that is designed to not only protect the drinking water supply but also the users within the building.

Individual (Point of Use) Protection

Individual (point of use) protection is a means by where backflow devices are installed on each potential source of backflow within the piping of a building/facility in order to protect the rest of the piping within that building/facility from potential contamination.

Zone or Area Protection

Zone or area protection is practiced within buildings/facilities where there exist both drinking and non-drinking water piping systems. This type of protection may also be practiced within the distribution system of a drinking water system in order to protect individual zones or areas from possible contamination from another zone or area within the distribution system.

Premise Isolation

Backflow preventers in this instance are typically installed within the facility on the service line connection to the drinking water supply.

Types of backflow protection applied under the backflow program

Premise isolation is the standard type of protection used. By installing a backflow prevention device at the water entry to the property, either at a perimeter meter or building meter location.

Perimeter meters

Meters that are installed at or near the property line in a chamber, pit or vault. This type of meter is typically found on large campus style properties that are of government or institutional use. In this case the premise isolation backflow device, based on installation requirements can be installed:

• in the pit, chamber or vault
• in an approved above ground structure, at the property line
• at the water entry to each individual building supplied by the perimeter meter

Building meters

Most properties in the city will have this type of meter installation. The meter is located at the water entry location of the building it serves. In this case the premise isolation backflow device, based on installation requirements is installed as close as reasonably possible to the water meter.

Area Protection is used in conjunction with premise isolation. This form of protection is necessary when there is an area that has a higher hazard classification than the building / property. An example would be a multi-tenant commercial building with a dental clinic in one of the units. The commercial building is classified as a moderate hazard and the dental clinic is classified as a severe hazard. To apply area protection to this example, a moderate hazard backflow device is installed for premise isolation and a severe hazard backflow device is installed for area protection. In this case, both premise and area devices are registered for annual testing.  

Annual testing

Backflow preventers are mechanical devices with internal parts that wear out over time. Annual testing ensures that the device is operating properly. The Backflow Program monitors annual testing to ensure the protection of the city drinking water system.

If your backflow devices are registered and you have a CCN#, BSI offers a list of qualified testers and device compliance information at BSI Online. (bsionlinetracking.ca).

Backflow Solutions Inc. (BSI)

Backflow Solutions Incorporated is a third-party company that specializes in backflow data management. The City of Ottawa has used the services of BSI since 2018 to manage and track annual backflow device testing. BSI sends communications to property owners including annual testing notifications.

Customer confirmation number (CCN) number

A Customer confirmation number (CCN) is generated by BSI to track premise isolation backflow devices that are registered with the city. The CCN number is used by Testers to submit test results through the Testers Portal on BSI. 

Backflow Hazard classifications

Assessing and Classifying Hazards

The backflow prevention program is tasked with assessing the risk or hazard of each potential cross-connection to the drinking water supply and whether the property owner has implemented the appropriate protections for that category of risk. The CSA B64.10-23 standard defines hazards to the drinking water system in three categories; Severe, Moderate and Minor.

• Minor is nuisance to the water supply and results in a reduction in only the aesthetic quality of the water.
• Moderate is any minor hazard connection that has a low probability of being a severe hazard.
• Severe is any type of cross-connection or potential cross-connection involving water that has additives or substances that, under any concentration, can create a danger to health.

Each type of facility (industrial, commercial, institutional) and residential building (multi-tenant vs. single family) connected to a drinking water system presents different hazards. For each hazard category, the backflow prevention program identifies the kinds of protections needed.

Types of backflow devices for premise isolation

There are a variety of backflow prevention assemblies and devices designed to protect the levels of hazard. The CSA B64.10 standard and the Canadian Cross Connection Control Manual provide a guide for the assessment of hazards and the selection of backflow preventers for both internal and premise protection.

There are two types of backflow prevention devices (or assemblies) common in achieving premise isolation:

Double Check Valve Assembly (DCVA): Required for facilities classified as moderate hazard.

Reduced Pressure Principle Assembly (RP): Required for facilities classified as severe hazard.

Property types identified

The Backflow Prevention Program will impact approximately 15,000 classified as severe or moderate risk, per the CSA B64.10 Standard. Properties identified have a higher probability of contaminating the city water distribution system should a backflow event occur. 

Affected properties:

• Moderate to Severe hazard classification (CSA B64.10 Standard, Table B.2)
• Industrial use
• Institutional use
• Commercial use
• Part 3 Residential properties (the Ontario Building Code identifies Part 3 residential properties as greater than 3 storeys or 600 m² in size.)

If your property is affected by the program a premise isolation survey will be required to start the compliance process. 

A premise isolation survey is a detailed assessment of the property in relation to the CSA B64.10 standard and the Ontario Building Code. An online form is to be completed by a qualified person and submitted electronically through the city web page to the Backflow Program. This is required for the following:

• New construction
• Renovations
• Existing buildings

New construction

• All premise isolation backflow devices being installed require a permit
• New building construction is done under a permit that does not identify the premise isolation backflow device. Nor is the required documentation provided to the program upon project completion.
• A premise isolation survey is required to complete the registration process

Renovations

• All premise isolation backflow devices being installed require a permit
• Renovations are done under a permit that does not identify the premise isolation backflow device. Nor is the required documentation provided to the program upon project completion.
• A premise isolation survey is required to complete the registration process

Existing building

• All premise isolation backflow devices being installed require a permit
• A premise isolation survey is required to start compliance process
• Applications for a permit are made through Building Code Services.
  • Permit application guidance document [ 245 KB ]

See the step-by-step requirements toward compliance below for more information.

In January 2018 the City began notifying affected property owners of the requirement to submit an initial survey. Properties with severe risks were addressed first followed by moderate risks. Notification of all initially identified property owners was complete by the end of 2023.

Severe hazard properties

Owners of severe hazard properties have:

• 1 year to complete a premise isolation survey
• 1 year to install backflow devices.

Moderate hazard properties

Owners of moderate hazard properties have:

• 1 year to complete a premise isolation survey
• 2 years to install backflow devices.

Please note:

Deadlines are based on the date that a property owner receives initial written notification from the City.

Steps toward program compliance

Step 1: Initial notification letter from City

The property owner receives by mail a notice to survey. Requesting that a premise isolation survey be carried out by a plumber or other qualified person for the identified property.

Please note: The Backflow Prevention Program asks that the property owners receive initial notification before conducting any work on the property.

Step 2: Hire a contractor

The property owner must hire a qualified person, as defined by the City’s Water By-law to conduct a Survey of Premise Isolation for the identified property.

Step 3: Submit survey results

The qualified person submits a Survey of Premise Isolation to the Backflow Prevention Program for review.

Step 4: Review of survey and City’s response

The Backflow Prevention Program reviews the Survey of Premise Isolation. The property owner(s), building contact and the qualified person (who completed the premise isolation survey) receive a survey response letter, by email with instructions on the next steps:

Notice to Obtain Building Permit

• Apply for a Building Permit through Building Code Services.
• Permit application guidance document 
• qualified person to install the backflow assembly identified in the survey response letter.

Notice to Repair Existing Device(s)

• Contact Building Code Services to confirm if a Building Permit is required before making any repairs. If required, apply for a Building Permit through Building Code Services.
• A qualified person to make the required repairs to the backflow device(s).

Notice to Test Existing Device(s)

• For existing backflow device(s) identified in the submitted Survey of Premise Isolation,
• test results are required to be reported to the Backflow Prevention Program by a qualified tester within 60 days from the date of Notice to Test Existing Device(s) letter.

Step 5: Submit documentation to the City of Ottawa

Once the Survey of Premise Isolation has been reviewed and all necessary action has been taken to install and/or repair devices, the City of Ottawa Backflow Prevention Program will register the installed devices with BSI.

To register new devices. Send the following to backflow@ottawa.ca to complete registration:

• Final inspection report
• Engineers’ conformance letter
• Device test reports

The device will then be registered with BSI and a CCN# created

To register existing devices. Send the following to backflow@ottawa.ca to complete registration:

• Device test reports

Step 6: Submit test results for device(s) to the City of Ottawa

Once the premise isolation backflow devices are registered, the City of Ottawa will begin tracking the annual test results of each device. Testing must be done by a qualified tester and the results must be submitted to the City of Ottawa through Backflow Solutions, Inc. (BSI) Online.

Extension Requests

Extensions to premise isolation survey and device installation deadlines are available on a case-by-case basis. An extension request must be completed before your due date passes. A permit application number is required for device installation extensions.

Exceptional circumstances

• Owners of moderate risk properties that require a significant investment in backflow device installations may request additional time to complete the work. Submit a plan by the site survey deadline for review and approval, providing a rationale for the request and demonstrating how installations will be complete by 2027.

Properties scheduled for demolition within the implementation timelines may be exempt from the requirements. Submit a demolition plan by the site survey deadline for review and approval.

Responsibilities of the property owner

All affected property owners will be required to hire a plumber or other qualified person to:

• Conduct a premise isolation survey
• Install premise isolation backflow devices
• Test backflow devices
• Conduct follow up premise isolation surveys every 5 years

Notify the Backflow Program within 30 days of:

• Change of ownership
• Demolition
• Change of hazard classification

The property owner is the owner of the backflow prevention devices and assemblies. The rationale is that the potential cross-connection was created by the property owner, or its tenants connection to the water distribution system, and therefore the property owner should be responsible for providing the protection.

In this case, as owner of the device, the property owner is responsible for installing, maintaining and testing the backflow prevention device in accordance with best practices and the backflow prevention programs requirements.

Note - tenants that have a City of Ottawa water account may receive a notice to survey letter. If you are not the property owner, please contact us and/or provide the letter to the owner.

Costs

The costs associated with the installation of a premise isolation backflow device depend on the size of the project, the type of device required and site conditions. Due to these parameters it would be difficult for program staff to provide an accurate estimate. Qualified contractors are better equipped to provide an accurate quote for your project.

The City of Ottawa does not offer any financial support for the costs incurred by property owners in relation to the program.

Permit

It is a building code requirement for industrial, commercial, institutional and Part 3 residential buildings make permit application for any construction and alterations designed by an engineer. 

All premise isolation backflow device installations require a construction permit to be installed. In order to apply for a permit you will require the following:

• Completed premise isolation survey
• Survey response letter
• Engineer stamped drawing

See Building Code Services and Permit application guidance document for more information on permit applications.

Once the premise isolation backflow devices are registered, the City will begin tracking the annual test results of each device. Testing must be done by a qualified tester and the results must be submitted to the City of Ottawa through Backflow Solutions, Inc. (BSI) Online.

BSI offers a list of qualified testers and device compliance information at BSI Online. (bsionlinetracking.ca).

Responsibilities of Contractors / Qualified persons

Property owners are responsible for retaining a qualified person who meets the requirements established under Water By-law 2019-74 to complete:

• Premise isolation surveys
• Premise isolation device installations, repair and maintenance
• Annual device testing

Water By-law 2019-74 identifies who is a qualified person.

Qualifications and training needed to conduct site surveys, install backflow devices and test devices are established in the Canadian Standards Association (CSA) B64.10 standards.

The City does not provide a list of approved service providers. Properties owners are asked to contact a local plumber and determine if they are certified with the Ontario Water Works Association (OWWA), which can be verified against the OWWA’s tester’s list using the plumber’s full name.

BSI offers a list of qualified testers and device compliance information at BSI Online. (bsionlinetracking.ca).

Premise isolation survey requirements

A qualified surveyor is a:

• Certified Cross Connection Control Specialist as per the Ontario Water Works Association (OWWA), and
  • Licensed master plumber, or
  • Journeyman plumber, employed by a licensed plumbing contractor
• Professional engineer
• Certified engineering technologist under the direction of a professional engineer.

Premise isolation backflow device installer requirements

A qualified person to install, relocate or replace a backflow prevention device is a:

• Licensed master plumber, or Journeyman plumber, employed by a licensed plumbing contractor; or 
• Apprentice plumber, employed by a licensed plumbing contractor and under supervision of a journeyman plumber or master plumber; or
• Industrial millwright licensed by the Ministry of Environment and Climate Change (MOECC) as a Water or Wastewater Operator. Industrial millwrights who are licensed by the MOECC as a Water or Wastewater Operator can install, replace, test and repair devices for water and wastewater systems.

Premise isolation backflow device tester qualifications

A qualified person to test and repair a backflow device is a:

• Certified Cross Connection Control Specialist as per the Ontario Water Works Association, and at least one of the following:
  • Professional engineer
  • Certified engineering technologist under the direction of a professional engineer  
  • Licensed master plumber
  • Journeyman plumber, employed by a licensed plumbing contractor
  • Apprentice plumber, employed by a licensed plumbing contractor and under supervision of a journeyman plumber or master plumber
  • Industrial millwright (industrial millwrights can test devices, but not repair them)
  • Industrial millwright licensed by the MOECC as a Water or Wastewater Operator
  • Fire system sprinkler fitter (for fire protection systems only)
• Backflow device testers also need a current calibration certification through the National Institute for Standardization Technology for the test equipment to be used.
• Qualified testers must pre-register with Backflow Solutions, Inc. (BSI) Online and provide information on qualifications. Testers are also required to submit annual calibration test data for testing equipment.

Fire System Sprinkler Fitter qualifications

• Can complete a premise isolation survey for building fire protection systems only and in conjunction with either Professional Engineer, Engineering Technologist, Licensed Master Plumber or Journeyman Plumber

Install, repair, replace or test premise isolation backflow devices for building fire protection systems only.

The administration of the backflow program depends on the coordinated efforts of the Backflow Prevention Program and Building Code Services in support of the City of Ottawa as the drinking water system owner.

The drinking water system owner responsibilities include:

• providing safe water to all drinking water users, including facilities that may present a risk through cross-connections
• providing staff to administer the backflow prevention program
• identify affected facilities connected to the drinking water supply
• communicate with the property owner the results of the premise isolation survey and recommended actions for the protection, installation and ongoing testing of the backflow prevention assemblies and devices
• aiding property owners in navigating the compliance process

Backflow Prevention Program responsibilities include:

• Oversee administration of the program.
• Inform property owners about the program and their responsibilities.
• Send notifications on site survey and testing requirements.
• Allow testers to register and submit test results on behalf of owners.
• Provide access to owners to be able to review their test data.
• Track the City’s backflow device assets for maintenance and other purposes.
• Collect City administration fees from testers.

Building Code Services responsibilities include:

• taking applications for and issuing construction permits
• ensure that the proposed installation meets the requirements of the Ontario Building Code and CSA B64.10
• inspect newly installed devices and ensure that all code requirements are met
• approval of the installation

Contact us

Backflow Prevention Program  

(613) 580-2424, ext. 22299 or email backflow@ottawa.ca for questions regarding program compliance.

Building Code Service

613-580-2424, ext. 29312 or email buildingpermits@ottawa.ca for questions regarding their permit application.

The standards for backflow prevention are established in the Canadian Standards Association (CSA) Manual for the Selection and Installation of Backflow Preventers/Maintenance and Field Testing of Backflow Preventers (CSA B64.10) and the Ontario Building Code, as amended.

The program will require premise isolation (the separation of a property's private water system from the City's drinking water supply) for all severe and moderate service connections through the installation of premise backflow devices in accordance with CSA standards.

Water By-law explained

Schedule "I" of the City of Ottawa's Water By-Law (2019-74, as amended) guides the City of Ottawa’s Backflow Prevention Program by enacting into law the requirements of CSA B64.10 “Selection and installation of backflow preventers”. The Water By-law outlines the requirements necessary to protect drinking water quality by ensuring the appropriate installation and inspection of devices that prevent contaminated water from flowing back into the City’s water distribution system. The program supports compliance with the highest industry drinking water protection standards to ensure public safety and the long-term safety of our shared water resource.

The Backflow Prevention Program Report was approved by Council and:

• Outlines the Backflow Prevention Program Requirements and Implementation Plan
• Approved an amendment to the Water By-law 2013-360 to add Schedule “G” – Backflow Prevention Program, attached as Document 1 including, any required consequential amendments to the main By-law provisions with an in force date of January 1, 2018.

Legislation and Standards

The following legislation and standards are observed when administering a backflow prevention program.

• Building Code Act, 1992
  • Ontario Regulation 332/12, Building Code
    • Canadian Standards Association (CSA) (B64 Series Standards) – standard referenced in the Code for the selection and installation of backflow prevention devices
• Safe Drinking Water Act, 2002
  • Ontario Regulation 170/03 Drinking Water Systems Regulation,
  • Ontario Regulation 248/03 Drinking Water Testing Services,
  • Ontario Regulation 169/03 Ontario Drinking Water Quality Standards,
• Municipal Act, 2001
• Fire Protection and Prevention Act, 1997
  • Ontario Regulation 213/07, Fire Code

The Building Code includes provisions to prevent the contamination of the drinking water in plumbing. The Building Code is a regulation made under the Building Code Act, 1992 and sets out technical and administrative requirements that must be met when a building is constructed, renovated or undergoes a change of use.

The Building Code contains objectives and provisions to limit the probability that, as a result of the design or construction of a building:

• a person in or adjacent to the building will be exposed to an unacceptable risk of injury,
• a person will be exposed to an unacceptable risk of illness,
• a person in the building will be exposed to an unacceptable risk of illness due to unsanitary conditions caused by consumption of contaminated water; or
• the public will be exposed to an unacceptable risk of illness due to the release of hazardous substances from the building.

Part 7 of the Building Code specifically deals with plumbing and requirements associated with plumbing. Section 7.6 of Part 7 addresses the requirements for potable water systems and includes provisions to protect potable water systems from contamination. This includes the requirements that potable water systems be designed, fabricated and installed in accordance with good engineering practices (Article 7.6.3.1.), and that connections to potable water systems be designed and installed so that non-potable water or substances that may render the water non-potable cannot enter the system (Article 7.6.2.1.).

The Building Code also generally requires backflow preventers where either backflow or back-siphonage may occur from a source of potential contamination (e.g. Articles 7.6.2.2. and 7.6.2.3.). Premise isolation is covered in Article 7.6.2.6. of the Building Code. Article 7.6.2.4. deals with backflow from fire protection systems.

Section 20 of the Safe Drinking Water Act, 2002 expressly prohibits any person from causing or permitting anything to enter a drinking water system if it could result in,

• a drinking water health hazard;
• a contravention of a prescribed standard; or
• interference with the normal operation of the system.

Persons who allow contaminants to enter a municipal drinking water system and interfere with its normal operation have been successfully prosecuted under section 20 of the Act.

The CSA B64 standards require that the cross-connection control requirements meet all local, provincial and national building permit and code requirements. In Ontario, this includes the Building Code and local by-laws.

Enforcement of the By-law requirements

If a property owner does not comply with Water By-law (2019-74), as amended, BPP staff will initiate an enforcement application process. The areas identified for compliance enforcement are as follows: 

1. Initial mailout: 

• One year to reply to Notice to Survey 
• Reminder sent if not reply to in 12 months 
• Failure to comply results in enforcement measures. Enforcement letter sent with a 30-day due date. 

2. Installation deadlines: 

• Severe hazard Premise: 1 year 
• Moderate Hazard Premise: 2 years 
• Repairs: 90 Days 
• Failure to comply results in enforcement measures. Enforcement letter sent with a 30-day due date. 

3. Annual Inspection: 

• Once devices are registered with the program, an annual inspection is required to maintain compliance with the program. Failure to test or report a test would result in enforcement measures. 

4. 5-year survey: 

• A survey of premise isolation is completed and submitted to the City by a Qualified Person as set out in the City Water By-law 2019-74, as amended, for Premise isolation, every five (5) years from the date of the completion of the first survey; or within thirty (30) days of any Hazard level increase, unless otherwise required by the General Manager. 

5. Backflow Device Repair / Replacement 

• Should a backflow device fail an initial or annual test and require repair or replacement, BSI emails BPP informing of the failed device. If the repair not completed within 30 days and no response received, will result in enforcement measures.
• If a backflow device is not properly installed based on the information submitted in a survey or as per the Ontario Building Code (OBC) or Canadian Standards Association (CSA) B64.10.  If no response to the Enforcement Letter after 30 days, will result in enforcement measures.

6. Surveyor / Tester infractions 

• If it is found that a contractor knowingly submitted false or inaccurate information on a survey or backflow device test report, will result in enforcement measures.
• Unqualified persons attempting to submit a survey or device test under their name or by using the license number of a qualified person, will result in enforcement measures.

Set Fines 

Part 1 Provincial Offences Act 

CITY OF OTTAWA – BY-LAW NO. 2019-74 – TITLE: Water By-law 

• Canadian Standards Association: Product Certification & Standards Development - CSA Group
• Ontario Building Code: O. Reg. 332/12: BUILDING CODE (ontario.ca)
• Watts Case Studies:
  • untitled (wattswater.com)
  • 553732.pdf (watts.com)
• This document was created with the assistance of A Guide for Drinking Water System Owners Seeking To Undertake a Backflow Prevention Program | ontario.ca

Other water related services offered by the City

• Meters: Water meters and repairs | City of Ottawa
• Water permits: Building retrofit water and/or sewer service connections | City of Ottawa
• Residential protective: plumbing Residential Protective Plumbing Program | City of Ottawa
• Building code permits: Do I need a building permit? | City of Ottawa

Additional resources

• Water By-law: Water (By-law No. 2019-74) | City of Ottawa
• Backflow Solutions Inc (BSI): HOME - BSI Online.CA
• Ontario Water Works Association (OWWA): Ontario Water Works Association - The Leading Resource for Ontario's Water (owwa.ca)

Property Owners

• OWWA testers list: Tester List (owwa.ca)
• BSI (owners page): BSI Online. (bsionlinetracking.ca)
• Building Code Service (BCS): Do I need a building permit? | City of Ottawa

Contractors

• OWWA testers list: Tester List (owwa.ca) 
• BSI (sign-in page): HOME - BSI Online.CA
• Building Code Service (BCS):  Do I need a building permit? | City of Ottawa
• CSA B64.10: CSA B64.10:23/CSA B64.10.1:23 | Product | CSA Group
• Pylon: Contact Us | Pylon Electronics