Recirculating Sand Filters are a packed bed reactor treatment system. Waste enters a septic tank for settling and primary treatment. The settled effluent then passes into a tank where it is recirculated through a sand filter bed (approx 8m2). The sand provides a high surface area media for aerobic bacteria. The aerobic bacteria break down the waste to provide a high quality treated effluent, which is then pumped from the discharge chamber to the irrigation disposal field.