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.
Septic tank
In Northern Ireland, the Department of the Environment must give permission for all wastewater discharges where it is proposed that the discharge will go to a waterway or soil infiltration system. The discharge consent will outline conditions relating to the quality and quantity of the discharge in order to ensure the receiving waterway or the underground aquifer can absorb the discharge.