“Mapping Potential Septic Contamination in Household Groundwater Sources Using GIS: A Case Study of Trento, Agusan del Surâ€

This study examines the potential contamination of water sources by septic systems used by households in Trento, Agusan del Sur, where site-specific conditions and local groundwater flow are often overlooked when installing septic systems and wells. The research focuses on the risks posed to household water sources by potential septage contamination, with water source and septic system locations identified through a ground survey. The radial distances between septic systems and water sources were analyzed using Geographic Information System (GIS) techniques, specifically Multiple Ring Buffer Analysis. Risk assessments were based on the minimum standard distance of 10 to 30 meters, as outlined in the Code on Sanitation of the Philippines, P.D. 856. The results reveal on a potential risk analysis using thematic mapping and multiple-ring buffer analysis further illustrates that approximately 84% of wells are situated within a 10-meter radius of septic tanks, classifying them as Very High Risk for contamination. In addition, only 6.64% of households surveyed are aware of the standard septic-to-water source distance, suggesting a significant gap in public awareness regarding sanitation safety standards. The study also highlights the reliance on water refilling stations (62.1%) as the primary drinking water source, with 16.7% of households still depending on wells, which are vulnerable to contamination. These findings highlight the necessity of stronger legislation, increased public awareness, and better sanitary infrastructure in order to avoid waterborne illnesses and protect public health.