Dealing with greywater

While your waterless compost toilet will eliminate blackwater discharge from your household, you will still need to deal with the greywater from your kitchen, laundry and bathroom.

Over the past 30 years, VIROtech has developed guidelines to help you build a simple, inexpensive greywater disposal system which almost all local councils are now happy to approve.* Greywater systems are very site-specific and must be designed to suit your soil type, slope and proximity to water courses, but it could be as simple as some perforated poly pipe along a row of trees. Talk to us about a system for your place.
*Local council approval is required prior to installation.

Simple & Inexpensive
The first rule is you DO NOT store greywater. When you store greywater the anaerobic bacteria population explodes and creates odours, so the greywater should be dispersed into the soil immediately. It can be used to irrigate trees and shrubs but not on your vegetables.

​This diagram shows a typical design using standard plumbing fittings, but is only appropriate if the block meets certain criteria regarding soils, slope, water courses, etc. The sub-surface irrigation can be constructed using commonly available plumbing materials such as polypipe. VIROtech can help you adapt this simple design to your particular block. 

Council may require an 'Onsite Sewerage Management System' application. The application is more likely to be approved if it is drafted by a suitably qualified geo-tech, so we suggest you engage a local who has experience with your local council. Many geo-techs will work from a standard set of design templates, which may be more complicated and expensive than necessary for a greywater only system, so we suggest you put them in touch with VIROtech so we can explain the principles of this simple system before they draft your application.

Greywater Pre-Filter
Our greywater pre-filter (GWPF) is a passive device which has a coarse filter and contains loose plastic aggregate. The greywater passes through two coarse filter socks to remove solids such as lint and hair, then splashes its way down through the coarse plastic aggregate and is slightly aerated. Aerobic bacteria growing on the surface of the plastic aggregate removes many of the organic compounds. The greywater flows straight through the pre-filter and out to your land application area (LAA) - normally a sub-surface irrigation system. The 260lt capacity of the GWPF acts as a buffer to allow peak flows to be dispersed in the LAA.

The improved condition of the greywater will extend the life of your land application area - in other words you can dispose of your greywater in the same place for longer. The filter socks might need emptying once a year - a 5 minute job.

The GWPF may not be a requirement for council approval, but can sometimes convince an otherwise sceptical council officer that you have put some careful thought into planning your greywater disposal system - thus avoiding the need for a more expensive system and the associated running costs. If your local council officer is reluctant to approve your greywater system, VIROtech is happy to contact them on your behalf and explain the system in terms they are comfortable with.

​We're with you all the way.

Greywater Flow Diverter
Some greywater systems may work better if the effluent is not directed to one area but dispersed across multiple areas. Our greywater flow-diverter automatically rotates supply to up to 6 separate areas as required.

This is sometimes useful when the area required to disperse all your greywater is not available at one location, or where you'd like to direct some of it to specific sites - e.g. orchards or gardens.

The valve is flow activated and can operate with as little as one metre of head. The hydraulic operation means no external power is required.