The traditional septic tank system as a method of effluent disposal is outmoded. There is an increasing demand for alternative wastewater treatment technologies to replace the more traditional methods. The bioMax range of ATUs manufactured by Durrant & Waite are a response to this need. Stringent design specifications and regulations controlling installation and maintenance of ATUs are a requirement to be met under Western Australian law prior to approval of any ATU system. However, despite this there are some concerns amongst environmental health officers that there is a significant public health risk associated with the method of aboveground irrigation. The information presented in this paper is designed to enable health professionals and interested parties to make an assessment of the application and operation of this type of technology on a more informed and objective basis.