The drawback of groundwater quality occurs due to minimum treatment of waste management in the landfill. The research objectives are to know the groundwater quality around the landfill study site, rainwater potential for drinking water purposes, and decreasing runoff due to rainwater harvesting technology implementation. The well water samples were collected from eight wells surrounding the landfill. Rainwater samples were collected from rainwater harvesting technology installation. Water quality parameters consist of total coliform, pH, and Total Dissolved Solids (TDS). Water conservation was observed by infiltration and precipitation. Total coliforms of well water are higher than rainwater. Furthermore, based on acidity and TDS values, well water is higher (pH 6.5-8.5 and TDS 188.8 + 128.7 ppm, respectively) than rainwater (pH 6.1 + 0.2 and TDS 8.4 + 1.4 ppm, respectively). Based on three parameters, rainwater is more proper for drinking water than well water in the study site. Rainwater harvesting technology is able to reduce runoff by 58.42% with the rainwater catchment area around 7,095 m2. Waste management in landfills should concern with groundwater pollution. Rainwater harvesting technology is a potential solution for drinking water supply in water crisis areas.