What is a Mound System?
Mound systems, conventional “septic” systems, in-ground pressure systems, at-grade systems, trench systems, etc. are all types of systems used to treat wastewater from structures not served by public sewer. They all do basically the same thing, they are just designed differently to compensate for differing lot constraints and soil conditions. A MOUND SYSTEM refers to a system in which the soil absorption part of the system must be designed and installed literally on top of the existing grade to assure the wastewater is properly treated on sites that have high groundwater or bedrock. In all Privately Owned Wastewater Treatment Systems (POWTS), including both mound and conventional systems in Wisconsin, the wastewater exits the house and enters a septic tank where the water is partially treated. In a septic tank the inlet and outlet of the tank are both near the top of the tank, allowing the larger solids to settle to the bottom of the tank. A portion of the solids accumulating on the bo
