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What plumbers need to know
Wastewater that's been used in homes and businesses can be recycled and used for many different purposes. We put it through a multi-step treatment process to remove impurities and treat it appropriately for its intended purpose. Similarly, plumbers must consider the end purpose and the level of treatment the water is receiving when they design plumbing systems.
Sydney Water recycling systems
We supply recycled water to homes and businesses through purple pipes. These pipes supply water for flushing toilets, washing clothes and outdoor uses such as watering gardens in homes and businesses.
Recycled water isn't intended for drinking, so it's not treated to drinking water standards. This means the plumbing must be kept separate from the drinking water pipes and clearly identified as recycled water. Read more about how we’re producing recycled water and what it can be used for.
Purple pipes supply recycled water to homes and businesses.
Private recycling systems
The NSW Government also encourages the private sector to implement innovative water recycling solutions through sewer mining and stormwater harvesting. Read more about these below.
Plumbing requirements
Recycled water is fit for purpose
Because our water resource recovery facilities treat recycled water according to how it will be used, recycled water plumbing requires particular care. There must be no cross-connection between water treated to lower levels and water treated for drinking or personal use.
NSW Health advises on and regulates the health aspects of recycled water use and quality. Building Commission NSW regulates and inspects recycled water plumbing.
Recycled water meters and fittings must be clearly identified using purple pipes and fittings.
Plumbing codes and standards
Only licensed plumbers can do plumbing and drainage work. This is particularly important for recycled water and greywater systems. We must ensure that non-drinking water is kept separate and clearly identified.
- Residential sites with recycled water have purple pipes, removable outdoor taps and warning signs on taps.
- Industrial sites can have different arrangements, including alternative colour coding or different on-site warnings.
Plumbers must follow the current version of the Plumbing Code of Australia and Australian Standard AS/NZ 3500. All pipes and products must comply with current Australian standards.
Visit Building Commission NSW for the latest requirements.
Plumbing inspections
NSW Fair Trading regulates and inspects recycled water plumbing to make sure it complies with the Plumbing Code of Australia and NSW Health guidelines.
Alterations, extensions and new recycled water plumbing must all be inspected. To book an inspection:
- pay the inspection fees online at NSW Fair Trading
- call NSW Fair Trading for an appointment or for more information about plumbing and audit inspections.
Building sites
On building sites, recycled water may be used for:
- dust suppression
- washing trucks and plant equipment
- watering gardens
- flushing toilets
- filling ornamental ponds.
If recycled water is supplied to your building site, it's probably not treated to drinking standard. You should ensure your workers understand what the water is and is not suitable for, and there are appropriate warning signs.
On construction sites, recycled water can be used for dust supression.
Recycled water produced from sewer mining can be used for irrigation.
Sewer mining
The NSW Government encourages private organisations to implement innovative recycled water solutions to secure Sydney’s water supply, particularly through sewer mining.
Sewer mining is extracting wastewater from a local wastewater system and treating it on-site using a small treatment plant. Recycled water produced from sewer mining is used:
- to flush toilets in commercial buildings and at industrial sites
- in cooling towers
- to irrigate sports fields, parks and golf courses.
Find out more about sewer mining and other ways we're producing recycled water.
Setting up a sewer mining scheme
Applying to set up a sewer mining scheme is a detailed process, requiring approvals from Sydney Water, your local council, and in some cases, the NSW Office of Environment and Heritage (OEH). You may also need to consult with IPART, and apply for a licence under the Water Industry Competition Act 2006 (WICA).
Completing a thorough investigation and concept review before making a formal application ensures you will have all the necessary information for us to properly assess your application. Learn more about how to apply:
- Read our Sewer mining fact sheet.
- Download our Request for preliminary advice on sewer mining proposal form.
- Review our Sewer Mining Agreement contract shell.
Stormwater harvesting
Stormwater is another source of recycled water. We work with local councils and other agencies to manage Sydney's stormwater. Most stormwater harvesting schemes are locally operated. We don't usually have a role in establishing or operating small local schemes. However, we'll help arrange access to the stormwater supply from our stormwater system. We also investigate opportunities to collect and reuse stormwater.
Stormwater harvesting involves:
- collecting stormwater from urban areas such as stormwater drains or creeks (not from roofs)
- storing the stormwater
- treating the stormwater so it can be reused as recycled water.
Cammeray Golf Club's dam is topped up with stormwater, which is used for irrigation.
Recycled water produced from stormwater harvesting is commonly used to water:
- public parks
- gardens
- sports fields
- golf courses.
Stormwater harvesting systems can be large or small. They usually consist of:
- an extraction point where stormwater is captured or diverted from a drain, creek or pond
- a network of pipes to transport stormwater from the connection point to the storage site
- a dam or storage tank where stormwater is temporarily collected for treatment and use
- a treatment system producing recycled water that is suitable and safe for its permitted use
- a network of pipes for distributing recycled water
- a system to manage by-products produced in the stormwater harvesting facility.
Guidelines and requirements
Recycled water produced from stormwater must be treated according to public health and environmental standards and requirements. The NSW Government has guidelines for Managing Urban Stormwater: Harvesting and reuse (2006).
These NSW Government guidelines provide an overview of stormwater harvesting and its potential benefits and limitations. They also provide information about planning and designing stormwater harvesting schemes to meet statutory and regulatory requirements.
Learn more
- Read our Stormwater harvesting facts sheet.
- Review our Stormwater Harvesting Agreement contract shell.