Grey water, rainwater, recycled water and reclaimed water: what's the difference?
These terms get used interchangeably, but they mean quite different things, with different rules about how they can be used at home. Here's a plain explanation of each, what they're used for, and an answer to a question we get asked surprisingly often: do they treat sewage so we can drink it?
The four types
Rainwater
Water collected from your roof into a tank. Commonly used for toilets, laundry and the garden. In town, NSW Health recommends mains water for drinking. See our rainwater tank guide.
Grey water
Used water from showers, baths, basins and the washing machine. Not from toilets or usually the kitchen. It can be diverted to the garden with approved systems, under conditions.
Recycled water
Wastewater treated at a plant to a standard suitable for non-drinking uses, such as toilets, gardens and laundries. Supplied through separate purple pipes in some newer areas of Sydney.
Reclaimed water
Another term for recycled water, often used for water reused in parks, sports fields and industry.
Grey water at home
- Grey water can carry soaps, bacteria and lint, so it shouldn't be stored untreated for long.
- Diversion devices that send it straight to subsurface garden irrigation are the simplest option.
- Treatment systems that let grey water be used for toilets or laundries need approval.
- Grey water must never be connected back into the drinking water supply.
Is sewage treated so we can drink it?
Not in Sydney at the moment. Sydney's drinking water comes from dams, supported by desalination. Sydney Water is exploring purified recycled water, highly treated wastewater added to the drinking supply, as a future source, and has said it could provide up to a quarter of Greater Sydney's water by 2056. Any change would need community consultation and government approval. In the Eastern Suburbs today, sewage goes to treatment plants and out to sea. See where does sewage go?
Plumbing rules to know
Any alternative water supply, whether rainwater, grey water or recycled water, must be kept completely separate from the drinking water, with the right backflow protection and labelling. That's work for a licensed plumber. We install and service rainwater tank systems and can advise on what suits your home, with a fixed price before any work starts.
Why locals call us
- Local to Matraville and the southern Eastern Suburbs
- Free on-site quotes, with a fixed price before any work starts
- Lifetime labour warranty on our workmanship
- 100+ five-star Google reviews
- Licensed plumbers and gasfitters (Lic. 398171C)
Common questions
What is grey water?
Used water from showers, baths, basins and washing machines, not from toilets.
Can I use grey water on my garden?
Yes, with an approved diversion device to subsurface irrigation, following the conditions that apply.
Does Sydney drink recycled sewage?
Not currently. Sydney's drinking water comes from dams and desalination. Purified recycled water is being explored for the future.
What is recycled water used for?
Non-drinking uses such as toilets, gardens and laundries, supplied through separate purple pipes in some areas.
Related help: rainwater tank guide, where does sewage go?, toilets on rainwater and backflow testing. Local pages: Matraville, Malabar, Maroubra and Pagewood. Browse all our plumbing guides.