The drained mound Geokit includes an anti-contamination geotextile, an LDPE film, a watertight cap flange and an adhesive flexible flange. The non-drained mound Geokit includes an anti-contamination geotextile and a filtration grid. Mounds are external sand filters. In fact, mounds are deliberately constructed elevated earthen structures. They consist of sand and gravels that ensure water purification process. This means brings an compulsory pumping of the pretreated effluents in case the house is not high enough. Like sand filters, they are available in drained and non-drained versions.