With water restrictions a recurring reality in the Free State, grey water reuse is increasingly practical for Bloemfontein homeowners. Here is what basic systems involve.
What is grey water
Grey water is wastewater from baths, showers, hand basins and laundry that has not come into contact with toilet waste. It is distinct from black water (toilet waste), which requires a septic or sewerage system to treat. Grey water can be reused for garden irrigation and toilet flushing with the appropriate treatment level.
Simple diversion systems
The simplest grey water system diverts the shower or bath waste to a storage tank rather than the sewer. From the tank, water drips to garden beds via low-pressure pipes. This works well for low-maintenance gardens but requires the water to be used within 24 hours because untreated grey water degrades quickly in warm conditions.
What plumbing is involved
A diversion valve splits the shower or bath outlet between the sewer and the grey water tank. This is a plumbing modification that needs a qualified plumber to install correctly, because incorrectly diverted grey water that backflows into the sewer system creates health risks. The storage tank and distribution system add to the scope.
Local regulations
Mangaung Municipality permits grey water reuse for subsurface irrigation within the property boundary. Overland spray irrigation with untreated grey water onto edible plants is not permitted. Grey water must not enter stormwater drains. Any system that connects to the municipal water supply requires a backflow prevention device.
Frequently Asked Questions
Can grey water be used to flush toilets?
Yes, with appropriate filtration and storage. Toilet flushing reuse requires a separate storage tank and a correctly installed feed system that cannot cross-connect with the potable supply.
Do I need council approval for a grey water system?
A simple garden diversion system may not require formal approval. Any system connecting to the potable supply system or discharging to the stormwater system requires approval. We advise on what applies to your specific installation.