Backflow refers to the reverse flow of potentially contaminated water entering the potable water supply. This can occur when there’s a drop in water pressure (back siphonage) or an increase in pressure from the downstream side (back-pressure). Both scenarios can draw and introduce pollutants or contaminants into the clean water supply, posing serious health risks.

An example of something back flowing In a typical mains water supply system, water pressure is maintained at a level above 140 Pa. This pressure is sufficient to ensure that water flows smoothly and consistently from your taps, showers, hand basins, and other fixtures.

However, if the water pressure is disrupted, reduced, or fails altogether—such as when a water main bursts, pipes freeze and draw from supply or the main supply is turned off for repairs—the situation can lead to what is known as backflow. During such events, water can flow backward from your premises into the main water supply, carrying potential contaminants with it.

Other common scenarios that might cause a drop in water pressure include fire-fighting efforts or a water truck filling up nearby. These activities can cause a temporary loss of pressure in the water supply, increasing the risk of backflow.
When backflow occurs, contaminants from your property—such as chemicals, bacteria, or other harmful substances—can be drawn into the mains supply. This contamination can pose serious health risks, leading to sickness or even death for anyone who consumes the affected water.

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Preventing backflow is essential to maintaining a safe water supply. While there are several methods to prevent both back siphonage and back-pressure, the most efficient, economical, and safest approach is the correct application of an appropriate mechanical backflow prevention device.

At Backflow Prevention Services, we offer a complete range of backflow prevention devices from trusted brands like Watts, Wilkins, Febco, Flomatic etc. We also have the local expertise to advise on the correct selection, application, installation, and servicing of these devices to meet the specific requirements of your site. It’s important to note that backflow prevention devices should not be installed in corrosive or polluted environments to ensure their longevity and effectiveness.

A backflow preventer is a device installed in a plumbing system to prevent the reverse flow of water, which could potentially contaminate the clean water supply.

It ensures that water flows in one direction only, protecting potable water from pollutants, chemicals, or other contaminants that could enter the water supply due to changes in pressure, such as back siphonage or back-pressure.
Backflow preventers are essential in safeguarding public health by keeping drinking water safe and free from contamination.

Annual testing of your backflow prevention device is essential to ensure it’s functioning correctly and effectively preventing contaminants from entering your water supply.

Over time, components within the device can wear out, fail, or become blocked, reducing its effectiveness. Regular testing helps identify and address any issues before they compromise the safety of your water system.

Additionally, many local and national regulations require annual backflow testing to maintain compliance and protect public health. Regular testing ensures your system remains reliable and meets all regulatory standards.

During a backflow test, a certified technician will perform the following steps to ensure your backflow prevention device is functioning properly:

1. Shut Off the Water Supply: The technician will temporarily shut off the water supply to isolate the backflow prevention device for testing – should not be more than 5 minutes.
2. Inspect the Device: The device will be visually inspected for any signs of wear, damage, or leaks that could affect its performance.
3. Test the Components: Using specialised testing equipment, the technician will check the pressure levels and functionality of the device’s internal components, such as check valves, relief valves, and air inlets. Each component is tested to ensure it is operating correctly and preventing backflow.
4. Record Results: The test results are recorded, detailing the condition of the device and whether it passed or failed the test.
5. Provide Maintenance if Needed: If the device fails any part of the test, the technician may perform minor repairs or adjustments on-site. If more extensive repairs are needed, they will advise you on the necessary steps.
6. Documentation: A test report is then typed up that includes any findings, repairs needed, and recommendations. This report is often required for regulatory compliance.
7. 12A Certification: Required for Building Warrant of Fitness (BWOF) and signals all backflows onsite have been tested and are functioning correctly.

Regular backflow testing ensures your device is functioning properly, protecting your water supply from potential contamination.

A 12A Certificate confirms that your backflow prevention device has been tested and is working properly. It’s often required as part of the Building Warrant of Fitness (BWOF) to ensure compliance with local regulations.

You need a 12A Certificate because:

• Compliance: It’s mandatory for meeting regulatory standards and ensuring public safety.
• Proof of Testing: It shows your device has been tested by a certified technician.
• Water Safety: It ensures your device is preventing contamination of the water supply.

Without a 12A Certificate, you risk non-compliance, fines, and potential water safety issues. Regular certification keeps your system safe and compliant.

An IQP (Independent Qualified Person) is a certified professional who is authorised to inspect and test specified systems, like backflow prevention devices, to ensure they comply with regulatory standards.

IQPs are typically required to carry out inspections and issue certifications, such as a 12A Certificate, as part of the Building Warrant of Fitness (BWOF) process.

Their independent status ensures that inspections are impartial and meet the necessary legal requirements to protect public health and safety.

Backflow risks can affect a wide range of industries and businesses where water or chemicals are used onsite. Some key examples include:

• Food Manufacturing: Ensuring clean, safe water in production is crucial for food safety.
• Dentists & Medical Facilities: Sterile water systems must be maintained to prevent contamination during procedures.
• Kitchens; Cafes & Restaurants: From commercial kitchens to cafeterias, backflow risks can compromise the water used for cooking, cleaning, ice machines, and coffee machines.
• Spray Painting: Water contamination from paint creates water safety concerns.
• Irrigation Systems & Swimming Pools: Cross-connections in irrigation can introduce contaminants into potable water systems.
• Hairdressers & Salons: Chemicals used during processes can potentially get into the fresh water drinking supply should backsiphonage occur.
• Science Labs: Contaminants can enter water systems without proper backflow prevention.
• Laundries: Backflow prevention ensures that water used in cleaning doesn’t mix with the public water supply.
• Mortuaries: Chemicals and fluids used in embalming and other processes pose significant backflow risks.
• Hospitals: Critical for keeping medical water supplies free from contamination.

And many more! Any business using water or chemicals on site — whether in manufacturing, services, or healthcare—face potential backflow risks. Proper backflow prevention measures are essential for the safety and compliance of your business and customers

Multiple backflow devices may be required on your site to protect different areas or systems with varying levels of risk. Each backflow device is installed to prevent contaminants from specific sources, such as irrigation systems, fire suppression systems, or industrial equipment, from entering the main water supply. Installing multiple devices ensures that all potential points of contamination are effectively safeguarded, providing comprehensive protection for your entire water system.

Understanding the terminology and abbreviations used in backflow prevention is essential for anyone dealing with water systems. Here’s a quick guide to some of the most common abbreviations you might encounter:

• RPZD (Reduced Pressure Zone Device): A backflow prevention device designed to protect water supplies from contamination by ensuring that water pressure does not drop below a safe level.
• DCV (Double Check Valve): A type of backflow prevention device that uses two check valves in series to prevent backflow. It’s typically used in medium hazard situations.
• Dual CV (Dual Check Valve): A simpler form of backflow prevention that uses two check valves in a single unit. It’s generally used in low-hazard situations.
• HCVB (Hose Connection Vacuum Breaker): A device installed on hose taps to prevent backflow when the hose is submerged in water or other liquids, protecting against contamination.
• AVB (Air Vacuum Breaker):

These abbreviations are commonly used in the industry to refer to specific types of backflow prevention devices, each suited to different levels of hazard and application needs.

HCVB (Hose Connection Vacuum Breaker): Installed on hose bibs, an HCVB prevents backflow by breaking the vacuum when a hose is submerged, protecting the water supply from contamination. It’s primarily used for hose connections in residential and commercial settings.

AVB (Atmospheric Vacuum Breaker): An AVB is used in broader applications, like irrigation systems. It prevents backflow by introducing air into the system when pressure drops, stopping contaminated water from reversing into the clean supply.

Key Differences:

• Application: HCVBs are for hose connections; AVBs are used in irrigation and plumbing systems.
• Location: HCVBs go on hose bibs; AVBs are installed upstream of valves or faucets.
• Function: Both prevent backflow—HCVBs by breaking the vacuum, AVBs by introducing air.

The selection and installation of the right backflow prevention device depends on the level of hazard present in your water system and is usually dictated by Council. Hazard levels are typically categorised into three types:

• Low Hazard: These conditions or devices may cause a nuisance but do not pose any risk to health or injury. In such cases, Individual Protection is installed at specific fixtures to prevent backflow.
• Medium Hazard: This category includes conditions or practices that could endanger health. For these situations, Zone Protection is used, with backflow prevention installed at connections to specific sections within a building.
• High Hazard: These are the most severe conditions, with the potential to cause serious health hazards or even death. For high hazards, Containment Protection is applied at the property boundary to safeguard the public water supply from contamination.

Changes in water quality—such as unusual odors, colors, or tastes—or even physical reactions to water contact could indicate a potential backflow incident.

Pinpointing backflow as the cause can be challenging. Several factors make detection difficult:

• Bacterial contamination is often short-lived and localised, making it hard to capture during routine sampling.
• Monitoring for chemicals and bacteria may not occur frequently enough to detect backflow-related contamination.
• Not all contaminants produce noticeable changes in color, odor, or taste, meaning they might go unreported by consumers.
• Customers may not always notice or report minor changes in water quality.
• Temporary reductions in water pressure, often caused by maintenance activities like flushing or line breaks, can go undetected.
• Health impacts linked to backflow are difficult to trace, especially when symptoms develop gradually.
• Localised contamination might not be widespread enough to draw the attention of public health authorities.
• Outbreaks of illness may not always be linked back to water quality issues due to limited information.