ABSTRACT
Septic tank systems are widely used in rural-residential locations for on-site disposal of household and institutional wastewaters, both in N.Z. and overseas. Design and installation practices have evolved from
early empirical approaches in the U.S. through to modern design guidelines based upon widespread research and performance studies undertaken from the mid-1960’s through to the 1980’s. A better understanding of
the mechanisms which contribute to good performance of soil infiltration and evapo-transpiration in disposing of effluent has led to development of alternative on-site systems for meeting specific
environmental and public health objectives in a range of climate and subsoil types. The use of soakage trenches and beds, evapo-transpiration systems, mound and fill systems have proved adaptable for a variety
of site specific requirements, and will ensure an important role for septic tank systems in servicing ruralresidential development for the future.
