Technology overview

Greywater technologies are best understood as system families rather than isolated products. A site may follow a diversion pathway, a treatment pathway, or a more developed response that combines several functional layers.

In practical terms, one project may need a diversion unit, filters, a pump, and a discharge arrangement. Another may need a treatment system, irrigation components, transfer hardware, and supporting maintenance parts. This is why technology choice should follow the project conditions rather than assumptions.

Greywater Diversion Devices (GWDD)

Greywater Diversion Devices are used where a project may suit a diversion-based response rather than a full treatment pathway. In general terms, they are associated with projects where the wastewater source, site conditions, and intended outcome make a simpler greywater pathway realistic.

That does not mean they are “basic” in a careless sense. A diversion-based response still needs to be matched properly to the source of the wastewater, the level of use, and the discharge or reuse arrangement.

In smaller residential projects, or in sites where there is already an existing wastewater response elsewhere on the property, a GWDD-style pathway may sometimes be the right direction. In standard residential projects, diversion may still be realistic, but the surrounding system often needs to be more developed.

Domestic Greywater Treatment Systems (DGTS)

Domestic Greywater Treatment Systems are treatment-based technologies used where the project is moving beyond a simple diversion response. This usually becomes more relevant when the wastewater is heavier, when kitchen wastewater is included, when the site is less forgiving, or when a more controlled outcome is needed before reuse or discharge.

A DGTS is not simply “a bigger diversion device.” It represents a different technology direction. The system is intended to improve the quality of the water before it moves into the next stage of handling.

In practical residential terms, DGTS technologies often become more likely when the home is standard full-time use, where the wastewater source is more demanding, or where the project needs a more refined and predictable pathway.

Commercial Greywater Treatment Systems (CGTS)

Commercial Greywater Treatment Systems are used where the scale, intensity, or nature of the project pushes beyond the normal domestic envelope. This can include shared-use, accommodation, public, commercial, or other larger-use situations where the wastewater response needs to be more developed than a typical residential setup.

The difference here is not only the equipment type. It is also the expected duty, the project context, and the level of performance control the site may require.

In other words, a commercial greywater response is usually not just a residential system made larger. It is often a different level of project altogether, with different expectations around scale, consistency, and supporting infrastructure.

Irrigation and discharge technologies

Greywater technologies are not only about diversion or treatment units. The way water is finally applied, distributed, or discharged also matters. In many projects, irrigation and discharge technologies are essential parts of the finished system.

Supporting greywater technologies

Many greywater projects rely on supporting technologies that do not define the whole system on their own, but still play an important role in making the overall response workable.

Why technologies are often combined

Real greywater projects often combine more than one technology family. A site may, for example, include collection, filtration, pumping, and irrigation hardware even if the overall pathway is still primarily diversion-based. Another site may include treatment, discharge hardware, and multiple supporting components as part of a more developed response.

This is why it is usually more useful to think in terms of technology layers rather than expecting a single product to represent the whole job. The final system is often the result of several technologies working together in one matched response.

In practical terms, project selection usually works best when the pathway is understood first, and the technology family or families are then matched to that pathway.

Where to Next?

These pages take you further depending on whether you want the parent overview, system logic, practical explanation, or help selecting the right enquiry path.