ABSTRACT
There are several technical methodologies for evaluating the ground water pollution potential of septic tank systems. Ground water modelling can be useful for evaluation of specific sites for systems, or even larger geographical areas that may be served by hundreds of systems. Modelling could be used to exclude septic tank system location on specific sites or in larger geographical areas. The chapter focuses on the application of existing technical methodologies not previously applied to septic tank systems. It describes the septic tank system as an area source of ground water pollution. The chapter explains the usage of models and selection criteria utilized. Information will then be presented on two empirical assessment methodologies and their application in a geographical study area; the Hantush analytical model; and the Konikow and Bredehoeft numerical model. Septic tank systems can be considered as area sources of ground water pollution, with the rectangular dimensions of the drainage field representing the source boundaries.
