The next step is determining the use of the grey water. It can be used for irrigation, flushing of toilets and supplying an air conditioning system. If grey water is used for irrigation, one has to look at hygiene as the water, which is not suitable for drinking, will be circulating in the garden and the garden taps. It is vital that the taps and pipework are identified properly as conveyors of non-potable water to avoid health risks. Using grey water for flushing toilets presents a perception problem as the water in the toilet does not look clean and is, therefore, not perceived as clean. This is why some owners and operators steer clear of this option. If the system is not designed properly and does not allow for proper evacuation of water, the building could flood, especially when the tanks are inside the building. In addition, if the filters do not function properly, an offensive odour could emanate from a grey water system therefore maintenance is vital.