Management of rural wastewater mostly involves on-site treatment as there is often no interconnecting means of treating numerous residences in the countryside. On-site systems can be subdivided into two broad categories: mechanical aeration systems and septic tank systems.

 

The mechanical aeration systems include biofilm aerated (BAF) systems, rotating biological contactor (RBC) systems, and sequencing batch reactor (SBR) systems. In these systems micro-organisms feed on organic materials to stabilise them, and reduce biological oxygen demand and suspended solids in the wastewater.

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The septic tank system consists of a septic tank followed by a soil percolation area. As an alternative to a conventional percolation area the effluent from a septic tank can be treated by filter systems such as mound or reed beds with sand, peat, plastic or reed filters followed by polishing filters. These polishing filters reduce the level of micro-organisms and nutrients in the wastewater.