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Controlling cross-connections and preventing backflow
Businesses

Does the City have a program to control cross-connections and protect the public water system?
Yes, we have a program to protect our drinking water from contamination caused by unprotected cross-connections. To keep the drinking water safe, we:

• inspect new construction and major renovations in non-residential buildings for compliance with cross-connection/backflow requirements
• approve the type of backflow prevention device and installation
• license backflow device testers
• require initial and annual testing of all backflow prevention devices
• ensure test kits are calibrated annually
• ensure public water outlets (hydrants and standpipes) are protected from cross-connections
• enforce the City of Winnipeg Water Works By-law

Are cross-connections regulated?
Yes. Cross-connections and backflow violate the By-law.

• It requires property owners to remove cross-connections from their plumbing system.
• If they cannot be removed, the owner must install proper backflow prevention devices.
• Owners failing to comply with the By-law may have their water shut off and/or be charged with violating the By-law

What is a cross-connection?
A cross-connection is an actual or potential connection between the drinking water supply and a source of contamination in a plumbing system. When a cross-connection is not properly protected, and a backflow situation occurs, contaminants can enter the City's drinking water system or the water pipes on your premises.

What is backflow?
Water normally flows in one direction, from the City's drinking water system to the pipes in your premises. Backflow is the flow of water in the opposite direction. Backflow can contaminate either the potable water within your building or the City's drinking water system.

There are two situations that can cause backflow:

1. Back-siphonage (decrease in pressure in the City system)

   • the pressure in the City's drinking water system drops due to activities that draw a lot of water from the system (e.g., firefighting, water main breaks, cleaning the water mains)
   • water in your pipes is sucked back into the City's drinking water system

2. Backpressure (the pressure in your system is greater than the pressure in the City system)

   • the pressure in your system increases (e.g., due to devices such as a booster pump, pressure vessel, pressure type chemical injector, boiler, or elevated plumbing)
   • water in your pipes is forced back into the City's drinking water system

What can I do to protect Winnipeg’s drinking water?
A correctly installed device will stop contaminated water from flowing into the City's drinking water system or into your own potable water system.

• In properties where there is a severe degree of hazard to public health, the owner must install a reduced pressure assembly on the incoming water service at the water meter location and/or at the sources of potential contamination.
• In properties where there is a moderate degree of hazard to public health, we recommend that owners install a double check valve assembly.
• In properties where there is a minor degree of hazard to public health, we recommend that owners install a dual check valve assembly.

How can I prevent backflow?
There are two ways you can prevent backflow:

1. An air gap. It is a vertical separation between the bottom of a tap and the upper water level of a receiving vessel. This separation must be at least twice the diameter of the tap and never less than one inch. For example, in a sink, it is the air space between the tap and the flood level of the sink. This space is great enough to prevent dirty water in the sink from contaminating the drinking water from the tap. An air gap is not always practical and can be easily bypassed.

2. A mechanical device which provides a barrier to backflow. The device stops the flow of water by automatically shutting the valve when water begins to flow backward. The main types of mechanical devices are:

   • reduced-pressure assembly
   • double check valve assembly
   • dual check valve assembly

Is a plumbing permit required when installing a backflow prevention device?
Yes, as required by the Winnipeg Building By-law 4555/87, a plumbing permit must be obtained from the City of Winnipeg Planning, Property and Development Department before installing or replacing new and existing testable backflow prevention devices.

Who can obtain a plumbing permit?
A plumbing permit will be issued only to a person who holds a Plumbing Contractor's Licence from the City of Winnipeg Planning, Property and Development Department authorizing that person to carry out a business or trade in the city of Winnipeg.

Who is responsible to test and maintain the backflow prevention device?
It is up to the property owner to ensure the device is:

• installed correctly,
• properly maintained and repaired,
• tested at the time of installation and once a year thereafter, and
• retested if any maintenance or repairs are performed on the device

Why do backflow prevention devices have to be tested annually?
Mechanical backflow prevention devices have internal seals, springs and moving parts that can become dirty and wear out. They must be tested annually with properly calibrated equipment to ensure they are working properly.

Who can test backflow prevention devices?
Only a tester licensed by us can test the devices to ensure that the internal check valves and mechanics are working properly.

How is the type of backflow prevention device selected?
The device is selected based on the degree of hazard to public health and the type of backflow it is controlling. There are three degrees of hazard:

1. Severe - any cross-connection or potential cross-connection to any substance that could be a danger to health. Severe hazards are typically found in industrial (chemical or processing plants), commercial facilities, hospitals and mortuaries. Examples of severe hazards for cross-connections are:

   • medical aspirators, bed pan washers, sterilizers
   • autopsy and mortuary equipment
   • lab bench equipment
   • food and beverage processing equipment
   • metal plating and chemical plant equipment
   • chemical and cleaning agents from car washes
   • petroleum processing and storage plant equipment
   • chemical and cleaning agents from commercial laundries
   • heating equipment
   • degreasing equipment

2. Moderate - any minor hazard that has a low probability of becoming a severe hazard. Moderate hazards are typically found in office buildings, schools, shopping malls, and high-rise buildings. Examples of moderate hazards for cross-connections are:

   • irrigation systems
   • swimming pools
   • vending machines
   • ornamental fountains

3. Minor - any cross-connection or potential cross-connection that is primarily a nuisance with a very low probability of becoming a health hazard. Minor hazards are typically found in residential homes, hair salons and restaurants. Examples of minor hazards for cross-connections are:

   • flexible shower heads
   • soda fountain dispensers
   • kitchen equipment
   • shampoo basins
   • distillers
   • water softeners

Contact us to find out if you need a backflow prevention device and the type of device needed.

Example from Winnipeg where a backflow affected the operation of a public facility:

• In February 2006, staff at a major health care facility noticed a distinct sweet smell coming from a tap. After investigation, we found that a ball valve was installed instead of a backflow prevention device on the plumbing system. Someone had mistakenly hit the valve, which allowed the contaminant from the cooling system to enter the facility's potable water supply. A backflow prevention device was installed, the system flushed and the problem corrected. There wasn't any illness reported due to this cross-connection, but the operation of this facility was impacted.

Example from Ontario where a backflow from a business affected their City water supply:

• In March 2005, a resident in Stratford discovered pink-coloured water coming from the taps in her home. An unauthorized cross-connection between a car wash and the City of Stratford water system allowed car-wash water to flow into the City of Stratford's distribution system. About 20 people reported to the hospital with symptoms that were consistent with chemical exposure. The car-wash water was responsible for the pink colour in the City of Stratford system, and the employee and the owner were charged and fined $75,000.00 for permitting a substance to enter a drinking water system.