Groundwater is an essential resource for domestic use, agricultural needs, and economic activities, yet it is increasingly threatened by contamination and overextraction. To evaluate groundwater quality and identify associated health risks, the Philippine Groundwater Health Index (PGHI) project conducted a comprehensive assessment of selected sites across various regions in the country.

The study analyzed groundwater samples from multiple locations to determine compliance with the Philippine National Standards for Drinking Water. Parameters assessed included organochlorines, heavy metals, microbial indicators, and physical and nonmetal characteristics such as phosphate and ammonia levels. Results were compiled to evaluate overall groundwater safety and identify areas of concern.

No organochlorines were detected in any of the samples, and all heavy metals complied with national drinking water standards. However, significant noncompliance was observed in other parameters. Microbial contamination was widespread, with 79.25% of samples failing to meet microbial standards due to the presence of fecal coliforms and Escherichia coli. Elevated levels of physical and nonmetal parameters were also noted, with 21 of 27 sites exceeding phosphate limits and 8 sites exceeding ammonia levels. These findings indicate substantial health risks associated with fecal contamination and nutrient pollution.

The PGHI project underscores the urgent need for enhanced groundwater treatment processes, regular monitoring, and strengthened policy-making to ensure safe drinking water. While the study provides critical insights, limitations such as lack of seasonal data, absence of emerging contaminant analysis, and limited spatial coverage highlight the necessity for continued improvements in groundwater management. Addressing these gaps is essential to protect public health, preserve environmental quality, and ensure the sustainable availability of safe groundwater for future generations.