Backflow Prevention Devices
PROTECTING PERTH’S WATER SUPPLY
WHAT IS BACKFLOW?
Backflow occurs when the pressure of the water mains is lower that that of the internal plumbing system, leading to back siphonage. This is caused by either a sudden drop in the water mains pressure, such as when a burst or ruptured mains occurs, or during periods of high demand, such as fire fighting, or from an over pressure on the private private property side.
If backflow occurs when a property’s drinking water is inadvertently connected with a source of contamination, such as through cross contamination or even a hose submerged in a container of liquid, then these pollutants could enter the water supply, posing a serious risk to our health, and in some cases, even death.
What is a backflow prevention device?
Backflow prevention devices prevent the above happening, protecting our water supply from harmful contaminates. They allow water to flow in one direction only, preventing it from flowing backwards and potentially contaminating the main water supply. They can only be serviced by licensed plumbers with the appropriate accreditation
An example of an RPZD
Types of Backflow Prevention Devices
There are three different levels of backflow prevention devices:
Containment protection: Device is installed at the property boundary, just downstream of the meter assembly serving the property and includes all fire services located at the boundary.
Zone protection: Device isolates an area or building within the property.
Individual protection: Device is installed at a point of potential contamination within the property.
Some examples of different types of backflow prevention devices include:
Garden tap - vacuum breaker / check valve (see more below)
Hot water units - check valve
Reticulation - dual check valve
Fire mains - double check valve
Highest level of protection (typically only seen on high risk contamination sites) - RPZD
Garden Taps
Your garden tap should have a vacuum breaker fitted. It stops the potential for the water in your hose being siphoned back into your drinking water. The taps you get off the shelf at most hardware stores don’t come with these so the vacuum breaker is a separate item that your plumber would install. We find these to be problematic over time however (they can’t be removed so if the vacuum breaker wears out or gets blocked you have to replace the whole tap) so analternative which we like to use are the Arco garden taps that come with built-in check valves.
Another early morning servicing a backflow prevention device
Some of our backflow servicing essentials
OUR SERVICES
We know what an inconvenience it is to have the water shut off so we’re happy to facilitate early starts to minimise disruption to your tenants and businesses.
Our annual backflow service includes:
Pulling apart and cleaning the inlet strainer
Carrying out minor repairs, where possible, within the test service charge
Porivision of quotes for any further works or replacements required
Submitting all required compliance results to The Water Corporation
To learn more about our backflow prevention installation, testing and repair services, click here.
We recently took over the service of this backflow prevention device. Although it’s been tested in the past, it doesn’t look like its strainer has ever been cleaned and this is what all the drinking water on the site passes through.