The importance of site assessment in designing effluent disposal areas

Abstract

This paper discusses a research project on on-site sewage treatment undertaken in the Brisbane area and will evaluate the treatment performance of on-site effluent disposal systems (septic tanks with absorption fields) and relate them to site and soil conditions. Detailed soil analysis was undertaken to evaluate soil physico-chemical characteristics at the study sites together with a comprehensive evaluation of site and landscape factors. The performance-based approach to domestic wastewater management introduced recently across Australia will result in a process in which site characteristics establish performance objectives for treatment and disposal. In designing and siting an on-site treatment system valuable information is derived not only by soil characterisation and terrain evaluation, but also observing geomorphologic features that are significant in relation to drainage. Soil chemistry can also add value in evaluating difficult sites. The results obtained confirmed the strong site specific nature of effluent renovation.