In order to develop low-cost energy saving ways to treat wastewater in combination with resource recycling, a plant bed filter ditch in which terrestrial and aquatic plants are used to remove nitrogen (N) and phosphorus (P) from domestic wastewater specially from the septic tank effluents. Discharging waste water into inland surface waters leads to contamination of water bodies is becoming a serious problem in Sri Lanka. Though there are several treatment methodologies adopted to treat wastewater, a low cost system with less maintenance is very much needed that suits small waste capacities and for domestic installation, so as to prevent release of nutrients to the natural ecosystem. Therefore this study focuses on introducing an ideal treatment system using a combination of bio and geo materials namely Geo Filter (BGF) ditches.

�A pilot scale Bio-Geo Filter ditches has been established at the Open University premises to demonstrate the potential for treatment of domestic wastewater using geo materials and plants. Selected bed filter materials and useful terrestrial plant species such as African merigold, canas, papyrus and reeds were employed for nutrient removal. This pilot-scale BGF containing laterite (kabook) stones with its rich composition of iron and aluminium, has been achieved nearly 100% removal of phosphorus.