Abstract. Clean and safe access to water is vital in human health and wellness, and thus regular water quality assessment is very important in avoiding waterborne disease and promoting public safety. Thus, the study aimed to assess the groundwater quality in Barangay Poblacion, Ayungon, Negros Oriental focusing on both microbiological and physicochemical parameters during dry and rainy seasons. The researcher utilized descriptive designs and employed simple random sampling. The water sampling was done during both rainy and dry periods at three groundwater sources for drinking. Microbiological and physicochemical analyses of the water samples were performed by third-party laboratories. The findings revealed that while the groundwater met the 2017 Philippine National Standards for Drinking Water (PNSDW) for total dissolved solids (TDS), color, nitrate, turbidity, arsenic, cadmium, lead, hardness, and heterotrophic plate count (HPC), it failed in terms of pH levels and coliform bacteria, indicating potential contamination risks. These findings emphasize the need for continued drinking water quality monitoring, enhanced sanitation practices, and sustained public education to ensure safe water consumption and prevent waterborne diseases.

Keywords: Microbiological; Physicochemical; Water quality; Assessment of groundwater quality.