Not every greywater project needs the same response. The right system direction usually depends on the wastewater source, the level of use, the intended outcome, and the site itself.
This page is designed to help you work out which enquiry path is most likely to suit your project before you contact WCTNZ®.
Most greywater projects become clearer once these four questions are answered honestly.
Bathroom-only greywater is a different starting point from kitchen-inclusive greywater. The source of the water often shapes the likely pathway first.
A lightly used tiny home is not the same as a standard family home, and neither is the same as a commercial or shared-use site.
Are you looking for a simpler discharge direction, irrigation reuse, or a more controlled result? The pathway changes depending on what the water needs to do next.
Available fall, pumping needs, discharge area, site layout, and general property limitations can all change what becomes realistic.
Most enquiries tend to fall into one of these broad groups.
Often lower-use, smaller-scale projects where the site may suit a simpler diversion-based direction, especially where there is already another wastewater pathway on site.
A more typical home project where the wastewater source, household use, and intended outcome may still suit diversion, but often with a more developed system response.
More likely where the wastewater mix is heavier, where kitchen wastewater is included, where the home is larger or more intensively used, or where the site is less forgiving.
More relevant where the project is accommodation, public, shared-use, or otherwise beyond the normal domestic envelope and needs a broader response.
Simpler greywater responses are usually more realistic where the wastewater source is lighter, the level of use is lower, the site is more forgiving, and the intended outcome does not demand a highly controlled result.
This is often the kind of project that leans toward a smaller residential or standard residential diversion-style enquiry. That does not mean the project should be treated casually. It simply means the likely pathway may sit closer to the diversion end of the scale.
Smaller projects, tiny homes, or sites that already have another wastewater response in place elsewhere on the property sometimes fit this direction more naturally.
Treatment becomes more likely where the wastewater source is heavier, where kitchen wastewater is part of the project, where the level of use is more demanding, where the intended outcome needs more control, or where the site itself places tighter limitations on what can be done simply.
This does not mean every kitchen-inclusive project automatically requires the same solution. But it often means the enquiry should move away from the simplest residential diversion assumptions and toward a more controlled treatment-led conversation.
In practical terms, if the project feels like it is moving beyond “light and simple,” a residential treatment enquiry is often the more honest starting point.
Many real greywater projects are not solved by one piece of equipment alone. A site may need a likely pathway and several supporting technologies working together.
That can include filters, surge or collection stages, pumping, transfer components, irrigation hardware, or a more developed treatment response depending on the project. This is why some enquiries are straightforward and others need broader scoping before the right system direction becomes clear.
If the site has multiple pressures at once — heavier wastewater, pumping needs, limited discharge options, or a more demanding outcome — it is common for the final system to involve more than one technology family.
If you are unsure whether the project is simple, standard, treatment-leaning, or commercial, that is usually the point where it makes sense to stop over-guessing and move into an enquiry.
WCTNZ® scopes greywater projects case by case. The enquiry process is there to help sort the project properly, not to expect you to arrive with a final technical answer already worked out.
The most useful thing you can do is provide clear starting information: project type, location, wastewater sources involved, expected use, site constraints already known, and what stage the project is at.
Use the option that best matches your current project understanding. If you are unsure, choose the most likely fit and include as much detail as you can.
Best for simpler greywater diversion situations where there is already a septic, sewer, or other wastewater pathway on site, or where a very small residential setup may suit a simpler system package.
Best for standard residential diversion projects where the site and wastewater source may still suit a diversion pathway, but with a more developed response than a very small system.
Best for residential projects that may require treatment rather than simple diversion, including more complex home wastewater layouts or projects involving kitchen wastewater.
Best for commercial, accommodation, public, shared-use, or otherwise larger-scale greywater projects where the team will assess the most suitable pathway for the site.
Copyright © 2025 Waterless Composting Toilets NZ Limited (WCTNZ®).
All rights reserved. This content has been reviewed and approved by Dylan Timney, Managing Director of WCTNZ®, who brings over 17 years of composting toilet expertise and 16 years of experience in building and eco-construction in New Zealand.
Last reviewed: March 29, 2026