Greywater is household wastewater that has not come into direct contact with toilet waste. In practical terms, it commonly includes water from showers, baths, hand basins, laundries, washing machines, kitchen sinks, and dishwashers.

Toilet wastewater is not greywater. That is blackwater, and it sits in a different category with a different management pathway.

Yes. WCTNZ® treats kitchen wastewater as greywater, not blackwater. However, it is usually a heavier and more demanding form of greywater because it can carry higher grease, oil, food solids, and organic loading than lighter bathroom sources.

Greywater is wastewater from non-toilet household sources. Blackwater is wastewater that contains toilet waste. The distinction matters because the reuse, discharge, and treatment pathways are not the same.

Yes, in the right situation. Greywater can sometimes support irrigation or controlled discharge outcomes, but reuse is not automatic. The wastewater source, site conditions, and system pathway all matter.

Often yes, but only where the source of the water, the system type, and the site conditions suit that outcome. Lighter greywater may suit simpler irrigation pathways more easily than heavier kitchen-inclusive greywater.

Greywater should not be casually stored for long periods. Once it sits too long, it can deteriorate, become more difficult to handle, and create odour or quality issues.

Short-term surge or collection stages are different. Those are controlled parts of system design, not long-term storage.

When greywater sits too long, solids can settle, odour can develop, and the water becomes less desirable to handle. That is why good greywater design usually focuses on prompt movement into the next stage of handling rather than simply holding it.

No. Not every greywater project needs the same level of system response. Some projects may suit simpler diversion-based pathways, while others need more controlled treatment, especially where wastewater loading, kitchen inclusion, discharge sensitivity, or site constraints increase the demands on the system.

Diversion is about moving suitable greywater promptly into an appropriate discharge or reuse arrangement. Treatment is about improving water quality first so the project can support a more controlled outcome.

Yes. In many projects, composting toilets and greywater systems are a logical pairing. The toilet changes or removes the toilet-waste stream, but the property still produces greywater from showers, basins, laundries, kitchens, and other fixtures.

Yes. A composting toilet may change the blackwater side of the project, but it does not remove the need to manage greywater properly. Greywater still needs its own suitable pathway.

Start with the wastewater sources involved, the level of use, the intended reuse or discharge outcome, and the site conditions. A very small residential project is not the same as a standard home, and a standard home is not the same as a commercial or shared-use project.

That is why WCTNZ® treats greywater as a project-by-project system question rather than a one-size-fits-all product choice.

Helpful starting details include:

• property type
• location
• expected use or occupancy
• wastewater sources involved
• site constraints already known
• what stage the project is at