Becoming more and more common. It is generally possible to retrofit a grey water system in a facility but a survey on a facility's existing system would have to be undertaken to determine whether or not it would be possible it also depends on the intended use of the grey water.

The size of the system could also be altered to cater for large and small facilities – even a single household. Grey water scheme was completed for a single household in Bloubergstran where the water was used for the garden and toilets.