This project is the first stage of a Demonstration of Innovative Decentralised Sewage Treatment Technologies and Management Systems Project. This first stage looks at both the development and application of a sustainability screening and evaluation tool. The tool is used to recommend a sustainable and appropriate technology option for community based wastewater systems. Its use is trialled in one of the Priority Sewage Program (PSP) areas at Galston High School. This site is considered appropriate for the technology demonstration as the soil horizon at the School is representative of the Hawkesbury-Nepean area (which the PSP area covers). That is, it has a clay layer overlaying a shale cap which overlays sandstone. The sustainability screening and evaluation tool was developed to address six key sustainability objectives (3 environmental, 1 technical, 1 social and 1 economic). A star rating system was developed, by which technologies (and technology options) for a specific site could be ranked and compared to determine which was the most sustainable and appropriate for that site. The tool is intended to be compatible with that developed by The Institute for Sustainable Futures and CSIRO in the Sydney Water Corporation Edmondson Park project. The six essential sustainability criteria were embedded in an 8-Step tool. The steps and their application to Galston High School are as follows: 1.Define effluent end-use scenarios. 2.Determine water and nutrient quality requirements for end uses. 3.Narrow selection of water quality requirements for site. 4.Generate and define process combinations to meet end uses. 5.Check minimum performance standards (PASS/FAIL). 6.Check appropriate fit-for-purpose water quality cascade. 7.a) Evaluate and rank technology options according to defined sustainability objectives and criteria. b) Address management issues. 8.Monitor and evaluate the chosen technology against objectives/criteria.