Groundwater Mapping of Total Coliform Contamination in Sleman, Yogyakarta, Indonesia

Abstract

Groundwater is a pivotal resource to supply clean and drinking water besides surface water. In Indonesia, there are various issues regarding groundwater quality and quantity. By increasing population growth has an impact on groundwater quality, such as generated pathogen contamination. To prevent groundwater pollution was used sanitation facilities were called communal WWTPs. Unfortunately, most WWTPs were not performing optimal, and some had already stopped operating. This study aimed to display groundwater quality using the Inverse Distance Weighting (IDW) for 2018 to 2019 in the Sleman Region of Yogyakarta Province. The spatial analysis was completed by observation and interview methods. The total coliform number was measured from 29 monitoring wells. The results explained that compared to 2018, groundwater quality in 2019 showed a decrease in contamination by pathogenic bacteria. Groundwater flows also shown the spread of contamination from north to the south area. The distance between monitoring well and septic tank or WWTPs outlet, depth, and the physical condition were substantial factors for spreading the contamination.