A review of history and theory of septic tank systems allows the establishment of guidelines for the design and construction of satisfactory and economical systems. While survival curves show that system life is usually short, proper design and construction supplemented by regular inspection and maintenance can adequately extend the expected life. It is recommended that a single drainfield design loading rate be applied to all installations meeting minimum topographical and geological requirements. Control should be exercised by a county regulatory agency and should be based upon engineering control of design in lieu of a codified approach. Periodic county inspection and regular maintenance by homeowners is essential, and can be implemented by an enforcement program based upon annually renewable septic tank use permits. An adequately designed, constructed and maintained septic tank system is more expensive than complete community sewerage, but is nevertheless economically feasible.