Backflow Prevention & Testing

Backflow Prevention & Testing: What Every QLD Homeowner Should Know

You’ve probably received a notice about backflow testing or noticed a small valve near your water metre without thinking much of it. After all, your tap water looks clean and safe – so it’s easy to assume everything is working as it should.

But when your home has a swimming pool, a rainwater tank, or an irrigation system, there are situations where water from those systems, carrying bacteria, dirt, and chemicals, can flow backwards into the main water line and contaminate your supply.

That’s why that valve is there – it’s a backflow prevention device, and it’s designed to stop that from happening. But it can only protect you if it’s working properly, which is why regular testing is needed.

In this guide, we’ll walk you through how backflow testing works, how often you need it, and what can happen if it’s ignored.

TL;DR

Backflow testing is a yearly check where a licensed plumber checks that your backflow prevention device blocks any reverse flow of water into your clean drinking supply.
Homes with high-risk setups like swimming pools with mains top-up, rainwater tanks connected to council supply, or irrigation systems are legally required to install and test backflow prevention devices.
The test is mandatory once every 12 months, with Townsville City Council maintaining a backflow register and issuing annual notices requiring compliance.
Only QBCC-licensed plumbers with a backflow endorsement using a calibrated test kit (checked yearly) can perform the test.
If the device fails the test, the plumber repairs or replaces faulty parts, retests it, and submits the report to the council. If it can’t be repaired, a full replacement is installed and reported.
A device can only be removed if the original risk no longer exists, and it must be removed by a licensed, endorsed plumber who confirms the property no longer needs protection and updates council records.
If you skip testing, you risk fines, water restrictions, council-ordered testing (at your cost), compliance action, and even insurance issues.

What Backflow Testing Actually Means

Backflow testing is a professional check to make sure your backflow prevention device is doing its job properly: stopping contaminated water from getting into your clean, drinking water supply.

Under normal circumstances, the flow of water is in one direction. Water moves from high pressure in the council water main (in the street) through your water metre into your house, which has lower pressure.

Sometimes, though, this process reverses. If the pressure in your home increases (higher than the street’s) or the pressure in the street decreases dramatically, the flow can reverse, and water moves from your house pipes into the street’s pipes.

To prevent this situation, a backflow prevention device is installed on your property (often near the water metre or at the points of connection for irrigation or tanks). It has a one-way check valve that allows water to flow in one direction only and automatically closes if the direction of flow is reversed.

Unfortunately, in Townsville, the hard water contains minerals, which can gradually build up inside the components within your backflow device. With the buildup of minerals, the components stick together or start wearing out, and eventually, the valve in the backflow device will not seal correctly. If the backflow device fails to close when flow is reversed, it won’t be able to prevent polluted water from contaminating the mains supply, letting bacteria and chemicals enter your drinking water and causing serious health problems.

That is why backflow testing is very important, as it verifies that your device correctly responds and closes off to the reversal of water flow.

Does Backflow Testing Apply to Your Home in Queensland?

Backflow testing only applies to your home if you have a testable device installed. In Queensland, these devices are mandatory if your property has medium- to high-risk water setups, like:

Swimming Pools: If your pool has a dedicated pipe from the mains to keep it topped up, then you’ll have a backflow prevention device to stop any chlorinated pool chemicals or nasty bacteria from flowing back into your home’s clean water supply in case the water pressure changes.
Rainwater Tanks with City Water Backup: If your rainwater tank system automatically switches over to council water when the tank’s water level gets low, then a backflow prevention device is required to ensure that any stale, stagnant rainwater that might be full of bird droppings and leaves doesn’t get pushed back into your clean council water supply.
Large Irrigation Systems: If you have a garden irrigation system that has a pump or injecter (adds pesticides/fertilisers), then these are high-pressure systems where chemicals are mixed into your water. If you don’t have a backflow prevention device and the main water pressure unexpectedly drops, it can suck water with pesticides and fertiliser from your tank.

How Often Is Backflow Testing Required in QLD

In Queensland, backflow testing must be carried out once a year.

The Townsville City Council keeps a database, or a backflow register, of all of the properties in the city with a testable device. Each year, they send you – the registered person – an invoice for your annual registration fee or a renewal notice. Once you get the notice, it’s your responsibility to make sure that the device gets tested by the end of the calendar year (31st December) and the fee is paid.

Who Can Legally Perform the Test?

In Queensland, only a plumber who meets the requirements below can perform the test:

A Current QBCC Licence: The plumber must be a licensed, qualified tradesperson registered with the Queensland Building and Construction Commission (QBCC).
The Backflow Prevention Endorsement: This is an additional qualification on their standard licence. It means they’ve undergone training in backflow prevention devices and are keeping their skills up-to-date with regular revalidation.
Calibrated Equipment: The plumber will use a special test kit to check your device. This kit needs to be calibrated every 12 months. The Council will know the kit’s up-to-date because the plumber is required to provide the kit’s serial number and its last calibration date on Form 9, which they submit after the test. If the kit is out-of-date, the Council will deem the test invalid, and you’ll be non-compliant.

Now, to know for sure that you’re choosing a qualified professional, just ask them, “Do you have a backflow endorsement, and is your test kit currently in calibration?” An expert will happily present their QBCC card, which shows ‘Backflow Prevention’ under ‘endorsements’ on the back.

Alternatively, you can quickly verify their credentials yourself on the QBCC Licensee Register online. All you need is their name or licence number to access their full details and ensure their status is active.

What Happens During The Appointment

The backflow appointment normally takes 30 to 45 minutes. Here’s a breakdown of what happens during that time:

Arrival and Visual Check: Your plumber will start by finding your backflow device (it’s normally located near your water metre). They’ll give it a visual inspection, looking for obvious problems like leaks or a damaged casing. They’ll also clear away any grass or mud that may have collected around the valve.
Internal Strainer Cleaning: The plumber will open the device to inspect the strainer, which is a metal sieve that captures small rocks, dirt, and mineral build-up from the water before they jam the valve. Once cleaned, your plumber will reassemble the device.
Water Off Time: To begin the test, they will turn off the main water supply to your home for 10-20 minutes because the water in your pipes needs to be completely still for the test results to be accurate.
Test Kit Connection: With the water off, your plumber will connect hoses from their test kit (a precise pressure gauge) to the test cocks. These are the small taps on the side of your device. This allows your plumber to measure the pressure on both the “street side” and the “house side” of the internal valve (check valve). They can then see exactly how much pressure is being exerted from each direction.
The Door Test: Inside your backflow device is a check valve that works like a one-way door – it should only open to let water into your house from the main street supply (which is at high pressure). Your plumber will use the test kit to apply pressure from the “house side” (the wrong way). If the pressure on the gauge remains constant, it means the door is tightly sealed and working as it should. If the pressure drops, there’s a leak in the seal, which means contaminated water could potentially seep back into the street mains.
Final Certification: Once all the testing is complete and your device has passed it, the plumber will turn your water back on and fill out a Form 9, which will be sent off to the Townsville City Council within 10 business days of the test. This form will inform the Council about:

The description of the land, address, and owner/occupier contact details.
The serial number, make, and model of the device, along with its location and size on your property.
The results of the test, including specific pressure readings (in kPa) and passing reports.
The details of the kit used to test the device.
The plumber’s name, sign, and licence number to confirm that they are a qualified professional.

Along with the completed Form 9, you pay the lodgement fee to the Council to ensure that your device remains registered for the rest of the year.

What If The Backflow Device Fails?

By Queensland law, if your backflow device fails, you have to get it repaired or replaced immediately. Most of the failures happen for small things, like a dried-out rubber seal or a bit of grit getting stuck in the valve. Your plumber will open the device, give it a good clean, and replace any worn-out rubber parts.

Once the repair is done, the plumber will test the device again. If your device passes the test this time, they will fill out a Form 9 to give to the Townsville City Council as your official “Pass” notice and note that your device was serviced to get it working properly again.

But sometimes, your backflow device is too old, or the metal itself is too corroded for repair. If that’s the case, a whole new backflow prevention device will have to be installed, and the new system will be tested. In this situation, your plumber submits two separate forms:

Form 9: Submitted to the Council with your new device’s serial number so they know you’ve installed one.
Form 4: A separate notice is sent to the QBCC, which is required any time a new piece of plumbing is installed on a property.

Very rarely, a plumber might not be able to repair your device on the spot if they don’t have a spare part or can’t find a suitable replacement. In such a case, they cannot leave your water system at risk. They’ll disconnect your water supply to the hazard appliance (like an irrigation system or pool) by turning off the valve to those appliances while leaving the rest of your house connected to the main supply, so you can carry out your daily activities until they return with the part.

Can a Backflow Prevention Device Be Removed Instead?

The short answer is yes, but only if the reason it was installed in the first place is gone.

If you’ve made changes to your plumbing that remove the original risk – like getting rid of a pool, switching from automatic sprinklers to a simple garden hose, or disconnecting a rainwater tank – you can remove the backflow prevention device, which simplifies maintenance and saves you money.

But even in these cases, you cannot remove the backflow prevention device yourself. To legally remove a device from the Townsville City Council’s register, you MUST hire an endorsed plumber (who has completed training in backflow prevention). The plumber will assess your property and make sure that removing the device won’t pose a risk to the city’s water supply.

The plumber will then remove the device and either permanently seal the pipe with a watertight cap to dead-end the line or reroute your plumbing into a standard, direct connection that no longer requires a specialised safety valve.

After the work is completed, they’ll submit a Form 4 to the QBCC (for the plumbing works), as well as a Form 9 to Townsville City Council stating that the device has been removed.

Once the council is notified, they may conduct a site inspection to verify that the hazard has been removed and, if satisfied, will remove your property from the backflow register. You will no longer have to test the system annually or pay the lodgement fee.

What Happens If You Skip Testing

If you miss your annual test, you may face the following:

Fines and Financial Penalties: If you fail to undertake the annual testing and maintenance within 60 calendar days of your last year’s device compliance test certificate (Form 9) expiring, the council will begin the formal process of issuing penalties. They’re calculated in “penalty units”, and a single fine can reach over $3,000 (20 penalty units).
The Show Cause Notice: If you continue to ignore reminders beyond that 60-day window, you will eventually receive a “Show Cause Notice“. This is a formal legal warning that basically says, “Tell us why we shouldn’t fine you and cut off your water.” You typically have between 14 and 30 days to respond with proof of a passed test.
Water Restrictions and Shut-offs: If no action is taken till now, the council can then issue an enforcement notice and take physical action. They can install a device on your water metre that restricts your flow to a trickle – just enough for a drink, but nowhere near enough for a shower or washing machine. For high-hazard properties, like a business using chemicals, the council may bypass the warning stages and issue an enforcement notice directly. In these extreme cases, they can turn off your water completely until the test is done.
Council-Ordered Testing (And The Bill): If no action is taken within 60 days of an enforcement notice, the council can send their own plumbers to your property to perform the test and any necessary repairs without your permission. You will then receive a bill for the plumber’s labour, parts, and a big administrative fee. If this goes unpaid, the costs are added to your property rates notice (your regular council bill for land and waste services). If you still don’t pay, they can take further legal action against you to recover the debt.
Insurance Issues: Imagine a backflow event occurs, and someone gets sick or your home gets damaged from a pressure surge. Your insurance company will look into whether you were keeping up with your annual testing. If you haven’t been, they could deny your claim, leaving you paying the bill for damages that can easily cost hundreds of thousands of dollars.

QLD Homeowner Checklist for Backflow Testing

During the Test

Ask for the “endorsement”: Double-check that your plumber has their backflow prevention endorsement on their QBCC card.
Calibration Check: Ask if their kit has been calibrated within the last 12 months. This is a must for your results to be valid in Townsville.

After the Test

Confirm Lodgement: Ask your plumber to confirm when they’ll be submitting the form 9 to the Townsville City Council. They’ve got 10 business days for this.
Keep Your Copy: You should receive a copy of the test report for your own records. Store this with your property documents.
Watch Your Rates: Check your next Townsville City Council rates notice to ensure the “Annual Backflow Fee” is listed. Seeing this charge confirms your property is correctly identified in the council’s system and your device is officially registered on the citywide database.
Set a Reminder: The Council will send you a notice, but it’s always a good idea to set a reminder on your phone for about 11 months from now to book in your next test early.

Final Thoughts

Backflow testing might not feel urgent, especially when your water looks clean, and everything seems to be working fine. But the risk isn’t always visible. If pressure changes and your device isn’t working properly, contaminated water can enter your supply out of nowhere, affect your health, and on top of that, you could face fines, penalties, or even water restrictions from the council.

That’s why you should always stay ahead of it. Just set aside one day each year and have a licensed plumber test the device, and you know everything is working as it should.

At 1touch Plumbing, we can take care of the whole process for you – from testing and any repairs to lodging the paperwork – so you stay compliant and protected.