The 4600 litre 17 person spherical septic tank including cover is manufactured from glass reinforced plastic (GRP) in accordance with BS 6297. Septic tanks consist of settlement chambers that retain sewage from the property for a sufficient time to allow the solids to form into sludge at the base of the tank, where it is partially broken down through anaerobic digestion. The remaining liquid then overflows from the tank by means of gravity into a subsurface drainage pipe.Septic tanks are used for domestic sewage disposal where connection to a main sewer is not practical. They achieve a high degree of settlement, producing a quality of effluent that is suitable for discharging to a land drainage system. All connections are 110mm PVC drain pipe. The Overall dimensions are 2080mm diameter x 3035mm high including 1m invert.