The effect of soil percolation rate on the efficiency garden of the safe water garden in Nagrak village, Pacet district, Bandung Regency

Clean water and good sanitation are the main basic needs as one of the supports for human health, and cannot be separated. Every living thing that consumes water and food as energy needs for activities will eventually produce waste. About 80% of clean water use turns into wastewater. If not managed properly, wastewater will have an impact on environmental aspects and human health. The problem that occurs today is that wastewater management has not been fully implemented in various parts of the world, especially in rural areas in developing countries. This is because developing countries are experiencing major problems in the social and economic fields. As an effort to overcome poor sanitation systems in various rural areas, especially in developing countries, Safe Water Garden (SWG) technology was introduced. SWG is a simple sanitation system (cost per unit only 4 million to serve 1-10 Families) that combines a septic tank and a 2x3 meter infiltration field (as recommended by Safe Water Gardens Pte Ltd.). In general, the treatment system, named SWG, has 4 main components, namely a closed tank, an infiltration field (garden), an interconnected piping system, and a dishwasher which is separate from the main system. As a further effort to reduce the need for costs, research was carried out at 30 SWG planning locations in Nagrak Village to identify cost requirements that could be adjusted to be efficient. Based on this, the SWG garden with a recommended area of 2x3 meters can be adjusted by considering land conditions and the amount of wastewater generated. In making these adjustments, a soil percolation test was carried out which refers to SNI 2389:2017 concerning procedures for planning a septic tank with advanced processing (infiltration wells, infiltration fields, up-flow filters, sanitary ponds) and calculation of wastewater generation that will enter the SWG system, so that efficient garden area calculations can be carried out. The results of this study reveal that as many as 25 SWGs can be built with less than the recommended garden size, 2 SWGs are in accordance with the recommended garden size, and 3 SWGs should be built with a larger recommended garden size. Therefore, taking into account the soil percolation rate and the amount of wastewater generated at the planning stage can provide efficiency to the SWG construction costs.