Evaluation of Microbial Contamination of Groundwater under Different Topographic Conditions and Household Water Treatment Systems in Special Region of Yogyakarta Province, Indonesia

Since the coverage of piped water is still only 20.1% in Indonesia, many people rely on groundwater for drinking and daily use, although the quality of the groundwater is not well understood. This study evaluated the influence of the topography, well type, groundwater abstraction depth, sanitation facility type, and distance between the well and the sanitation facility on the groundwater quality. In addition, a possible household treatment system was investigated based on microbial removal efficiency and household acceptance. The results showed the groundwater abstraction depth and well type were the most important factors in controlling microbial contamination. The sanitation facility type, except small-scale sewer systems, and the distance from a well were not significantly correlated with E. coli concentration. A high microbial concentration was found in a flat area with predominantly shallow wells, latrines, and septic tanks because the topographic conditions determined the commonly used well types and groundwater abstraction depth. The RO + UV system was the only system that assured microbial safety of treated water. The chlorination and microfiltration systems had difficulty with chlorine-dosage adjustment and microbial removal, respectively. Raising public awareness of water quality problems was found to be important to improve acceptance of household treatment systems.