WATER SERVICES

Greywater systems: what Victorian plumbers can and cannot connect

Greywater work sits inside tight boundaries: the plumber installs to the standard and to the approval that already exists, but the plumber does not grant that approval. Knowing where your scope starts and stops is the whole point.

Diversion versus treatment, briefly

Greywater is wastewater from sources like the shower, bath, and laundry. At a high level there are two kinds of system: a diversion system that redirects greywater for use without treating it, usually under restricted conditions, and a treatment system that processes it to a higher standard before reuse. Which one is permitted, and for what use, is set by the current approvals and the standard, not by what suits the job on the day.

Approvals are not yours to grant

This is the line that matters. Greywater systems generally depend on approvals that sit with the relevant authorities. As the plumber you install to the standard and to the approval that already exists; you do not decide whether a system is allowed, and you do not give approval advice. If the approval is not clear, that gets resolved before pipework goes in. Check the current approvals and the standard, and keep your work inside your plumbing scope.

Separation and signage

• Greywater pipework and outlets must stay completely separate from the drinking supply, with no cross-connection.
• Greywater pipework and outlets generally need to be identified so they are never mistaken for drinking water.
• The arrangement keeps greywater contained to where it is permitted to go.

Check the current standard for the exact separation and signage required for the system in front of you.

Your install and documentation duties

Inside your scope, the duties are clear: install to the standard, keep greywater fully separate from the drinking supply, identify the pipework, and record what you did. Photograph the separation, the identification and signage, and the connection points so the install can be shown to match the approval. Elemetric keeps that with the job.

Common questions

Can I just connect a greywater system if the customer wants one?

No. Greywater systems generally rely on approvals that sit with the relevant authorities, not with the plumber. Your job is to install to the standard and to whatever approval is in place. Check the current approvals and the standard before you start, and stay inside your plumbing scope.

What is the difference between a diversion and a treatment system?

At a high level, a diversion system redirects greywater for use without treating it, usually under restricted conditions, while a treatment system processes it to a higher standard. Which is allowed, and where, is set by the current approvals and standard, not by the plumber.

General information for licensed tradespeople, not legal or regulatory advice. The licensed plumber remains solely responsible for compliance. Refer to the current AS/NZS 3500 standards and the Building and Plumbing Commission (formerly the VBA) for authoritative requirements.