The on-site and decentralised industries impinge on over two million Australians and if current trends continue this number will rise substantially. Great changes are underway with decentralised principles being enforced in new building codes and developers actively seeking to recycle water from on-site treatment systems to help alleviate the shortage of freshwater. This impetus has meant a change in philosophy from a disposal to a recycling mentality. The changes in the field are beginning to have an impact on the way the subject/s are taught in the University sector and the way codes/legislation/guidelines are written by Government. The new philosophy has inspired a great deal of innovation in certain sections; however established manufacturers are slow or perhaps impeded from responding. The application of on-site and decentralised technologies into sites above 21 equivalent persons brings to the forefront challenges which in the past may have been neglected; such as the inflow water quality into a treatment system.