Cross Connection Control FAQ
This page contains answers to frequently asked questions (FAQs) about cross connection control and backflow prevention.
Cross Connections and Backflow Prevention
- What is a cross connection?
- What is backflow?
- What is back-siphonage and its causes?
- What is a back-pressure backflow?
- What are some typical cross connections found in a residential home?
- What will a backflow preventer do for me?
Backflow Preventers
- What is a backflow preventer?
- What is the typical cost of purchasing a backflow preventer?
Testing Backflow Preventers
- Why do backflow preventers have to be tested regularly?
- Who is responsible for having a backflow preventer tested?
- Who can test backflow preventers?
- I have received a letter stating that my backflow preventer is due for testing, what am I required to do?
- What are the consequences for failing to comply with the testing request?
- What is the typical cost of testing a backflow preventer?
Installing New Backflow Preventers
- Will a backflow preventeraffect my water pressure?
- Is a plumbing permit required when installing a backflow preventer?
Cross Connections and Backflow Prevention
What is a cross-connection?
A cross connection is a physical connection between a drinking water system and some other environment which could allow a backflow of contaminants to enter the drinking water. This could be a pipe connecting a customer's drinking water system to the heating/cooling system, fire system or irrigation system.
What is a backflow?
A backflow is an undesirable reverse flow of a substance (water or otherwise) through a cross connection into the drinking water system. A backflow can contaminate either the customer's drinking water system within a building or the public drinking water system in the street. Backflows can be caused in one of two ways: back-siphonage or back-pressure.
What is back-siphonage and its causes?
Back-siphonage can occur when reduced pressure in the watermain allows a siphon to start and contaminants to enter the main. Back-siphonage can be created when there is an interruption of the water supply due to nearby fire-fighting, repairs or breaks in water supply mains.
What is a back-pressure backflow?
Back-pressure backflows can occur when a system operating under a higher pressure than the pressure in the watermain forces the contaminants into the drinking water. Back-pressure backflows can be caused by high pressure pumps, temperature increases in boilers, elevated tanks or other pressure producing systems.
What are some typical cross connections found in a residential home?
The most common types of cross connections found in the home include:
- Garden hose attached to a outside tap or hose bibb with the end of the hose connected to a pesticide sprayer or left submerged in a ornamental pool
- Underground lawn watering (irrigation) system
- Laundry sink with submerged hose
- Handheld shower head immersed in water
- Hot water heating system
- Home fire protection system
- In-home water treatment (softener) system
- High pressure washer
What will a backflow preventer do for me?
A properly installed and working backflow preventer will protect your family from contaminants flowing backwards into your household drinking water piping.
Backflow Preventers
What is a backflow preventer?
A backflow preventer is a mechanical device that prohibits a backflow of contaminants from getting into the drinking water. The principal types of testable backflow preventers used for medium to high hazard processes include: reduced-pressure principle assemblies, double check valve assemblies and pressure vacuum breaker assemblies. Non-testable devices used for low hazard processes include: residential dual check valves and hose connection vacuum breakers.
What is the typical cost of purchasing a backflow preventer?
The cost of a backflow preventer depends upon the type of preventer and the size of the preventer. Typical costs are provided below:
| Backflow Preventer | Typical Cost |
|---|---|
|
$6-10 |
|
$75-150 |
|
$100-200 |
Testing Backflow Preventers
Why do backflow preventers have to be tested regularly?
Backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Therefore, backflow preventers have to be tested regularly to ensure that they are functioning properly. Typically, backflow preventers are tested once each year.
Who is responsible for having a backflow preventer tested?
Generally, the owner of the facility or facility manager is responsible for having the preventer tested. If the backflow preventer belongs to the tenant then the tenant is responsible for having the preventer tested.
Who can test backflow preventers?
Only an individual who is a Certified Backflow Prevention Assembly Tester and has been certified by the British Columbia Water and Waste Association is permitted to test backflow preventers located within the Greater Victoria Drinking Water Supply System.
I have received a letter stating that my backflow preventer is due for testing, what am I required to do?
Contact a Certified Backflow Prevention Assembly Tester to test the preventer. For your convenience, a list of companies employing Certified Testers is provided on this web site.
What are the consequences for failing to comply with the testing request?
Failure to comply with the notification may result in discontinuation of water service.
What is the typical of a backflow preventer test?
The typical cost of testing a backflow preventer is about $100.
Installing New Backflow Preventers
Will a backflow preventer affect my water pressure?
Yes, essentially all backflow preventers cause some degree of pressure loss. The typical pressure drop across a preventer depends upon the type, make, size and location of the device. Refer to the manufacturers literature exact information.
Is a plumbing permit required when installing a backflow preventer?
Any plumbing alteration related to the installation of a testable backflow preventer (RP, DCVA, & PVB) will require a plumbing permit. For permit information or inquires contact Building Inspections in your local municipality.