Homes not served by a public sewer must treat and disperse wastewater on the lot. Septic tanks with soil treatment systems (also known as leach fields) are a common onsite system. The septic tank removes most settable and floatable solids from the wastewater to protect the soil from clogging. The soil under the pipes buried in the yard filter out pollutants and pathogens to treat the wastewater before moving into groundwater or surface water.
