What purple or lilac pipe means
The colour is a warning label. It tells you the water in the pipe is not for drinking.
Purple, also called lilac, is the colour used in Australia for recycled and other non-drinking water. If a pipe or fitting is lilac, do not drink from it. And do not connect it to a drinking supply. The colour exists so people can tell the two systems apart at a glance.
Where you will see it
You will mostly see lilac pipe in new estates with a recycled water scheme. It carries treated water to garden taps, irrigation and, in some areas, toilet cisterns. Lilac taps are normally marked as not for drinking.
- Recycled water schemes. Treated water supplied to the property boundary.
- Garden and irrigation. Lilac taps and sprinkler fittings.
- Toilet flushing. In areas where the scheme allows it.
It is not the same as a rainwater tank
Rainwater piped to the toilet or laundry is a separate arrangement from a recycled scheme. Both are non-drinking, and both need to be kept apart from the mains. Some jurisdictions use the same colour for tank water that is plumbed to non-drinking uses, so check what applies where you live.
See non-potable water for what the term covers and which uses are normal.
Do not rely on colour alone
Older installs, repaired sections and pipes hidden in walls may not follow the colour rule. A pipe with no colour tells you nothing. A pipe you cannot trace is not safe to assume.
| What you see | What it usually means | What to do |
|---|---|---|
| Lilac pipe or tap | Recycled or non-drinking water | Do not drink; keep separate from the mains |
| Unmarked tap in the garden | Unknown | Do not assume it is drinking water |
| Lilac pipe near a mains pipe | Two systems side by side | Never join them |
If you are unsure, ask before you use it
Say you move into a home with lilac pipework and you are not sure what it serves. Ask the water authority for your area. They can tell you whether a recycled scheme is connected and what it is approved for. Ask before you fill a pool, water a vegetable patch or let children play with a hose.
What to do when you find an unfamiliar pipe or tap
Colour is a hint, not proof. Follow these steps whenever you meet a pipe you cannot explain.
- Stop using the tap for drinking, cooking or brushing teeth. You lose nothing by waiting.
- Note the colour and any label. Take a photo of the tap, the pipe and any tag or sticker.
- Trace where you can. Look for where the pipe starts and whether it runs close to a mains pipe. Do not cut, open or join anything.
- Ask the water authority for your area. They can tell you whether a recycled scheme serves the property and what it is approved for.
- Label the tap yourself. A clear tag as not for drinking protects guests and children.
- Call a licensed plumber if two systems look linked. A cross-link can contaminate the drinking supply.
Our page on non-potable water covers the normal uses once you know what you have.
Lilac pipe at a home you are buying or renting
Lilac pipework is a good question to raise at an inspection. It is not a fault, but it tells you the property has more than one water supply.
| What you see | Question to ask | Why it matters |
|---|---|---|
| Lilac pipe or tap outside | Is a recycled scheme connected? | It tells you which taps are not for drinking |
| Lilac pipe inside near toilets | What is the cistern fed from? | Some areas allow recycled water for flushing |
| Unmarked taps in the garden | Which supply do they serve? | Do not assume they carry drinking water |
| Lilac and mains pipes close together | Were they installed by a licensed plumber? | Two systems side by side must never be joined |
| Repaired or hidden sections | Are the old pipes still marked? | Colour rules may not have been followed on older work |
Ask the seller or agent for any plumbing paperwork. Our guide to how a rainwater tank is plumbed shows what a separate tank line looks like.
Frequently asked questions
What does purple pipe mean in Australia?
It marks recycled or other non-drinking water. Do not drink from it or connect it to a drinking supply.
Is lilac pipe the same as purple pipe?
Yes. Lilac and purple are used for the same purpose, which is to mark non-drinking water.
Can I drink water from a lilac tap?
No. Lilac taps are for non-drinking uses such as irrigation, and are normally marked accordingly.
Can I connect lilac pipe to my house water?
No. Joining the two systems can contaminate the drinking supply and is licensed plumbing work.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- NHMRC. Australian Drinking Water Guidelines
- Australian Building Codes Board. National Construction Code — Volume Three (Plumbing Code of Australia)