Mound System
Pressure-dosed sand filters placed above, and discharging directly to, the native soil. Their main purpose is to provide additional treatment to the wastewater before it enters the natural environment. Mound systems are designed to overcome site restrictions including poor soils and high groundwater. Mound systems consist of 1. a pretreatment unit (usually a septic tank), 2. a pump or dosing tank for pressure dosing, and 3. distribution laterals within the constructed mound for which effluent is delivered to the sand media where biological treatment takes place as the wastewater passes through to the native soil below for final dispersal. <