As the name suggests, backflow occurs when water flows backwards in the opposite direction of its intended course. This may occur due to back pressure or siphoning of the water. Backflow is essentially the mixing of safe, drinkable water with ‘dirty’ water. A backflow preventer can be installed to prevent this and should be tested to ensure it works properly.
Backflow Testing Basics
When a plumbing system is running smoothly, water pressure is maintained at a certain level to facilitate flow from pipes to the faucet. Sometimes leaking, or a burst pipe occurs which alters the water pressure and can cause backflow.
Back-siphonage occurs when there is a vacuum in the supply pipe line which is typically from a burst pipe, or similar breakage. Back-pressure occurs when the added pressure from outside sources such as pumps, boilers or tanks, is greater than the pressure within the supply line.
A backflow preventer, also known as a check valve, is a mechanical safety device installed to stop any cross-contamination of water. Many municipalities have bylaws which mandate that all homeowners and tenants regularly maintain and test their backflow devices. Backflow tests need to be performed at least once a year to ensure seals, springs and moving pieces are all functioning properly and not worn out.
During a backflow test, a certified tester performs a check valve analysis and provides a test report to indicate compliance with the bylaw. The test itself is a fairly quick and simple process. A certified tester connects a test kit to the backflow preventer and turns off all water downstream during the test. If repairs are needed, the tester will indicate so on the report.
Failure to maintain your backflow preventer can result in a fine or discontinued water service and cause possible illness from contaminated drinking water.
The Dangers of Backflow
If there are cross-connections between drinking water lines (potable water) and sources of non-potable water which contain pollutants or contaminants, your drinking water could become unsafe to drink. Safety of drinking water is of course dependent on the types of contaminant(s) leaked to your potable water source, and the length of time it has been sitting.
Unfortunately, cross-connections can’t always be eliminated which is why backflow water preventers and testing are so important. A few common cross-connection locations are:
- Irrigation systems (risk of fertilizers and/or pesticides)
- Heating or cooling systems (bacteria build-up from sitting water)
- Fire suppression systems (bacteria build-up from sitting water)
If you are concerned about the safety of your drinking water, or would like to schedule an appointment, call Mr. Rooter to learn more about backflow testing.