Effluent sewer
Effluent sewers also currently serve fewer people than septic systems, which also use septic tanks, but simply dispose of the effluent by draining it into a leach field. About one quarter of United States homes dispose of their wastewater with septic tanks. However, effluent sewers are being looked at as a sewage treatment solution in areas where gravity sewer systems are not well-suited or when the high capital cost to build a gravity system is prohibitive. Areas that are less than ideal for gravity systems include areas that are large, but extremely flat and areas that require long-distance pumping, such as where homes are widely spread out or when several small villages or towns connect their sewage systems so that a centralized plant can be built.
Lidcombe Hospital Precinct
The archaeological resource associated with the first septic tank constructed in Australia and the possible relationship between the irrigation system stormwater channel and the sewerage system has the potential to yield information about the development of the early sewerage system and its technical innovation. The remains of the septic tank itself are no longer within the hospital boundary, but pipes and channels and associated infrastructure are likely to be located in the Lidcombe Hospital Precinct. (The remains of the septic tank are in the University of Sydney Cumberland College campus).