Microbiological Compliance and Source Protection Gaps in Rural Drinking Water Systems of Camarines Sur, Philippines

Background: Microbiological drinking-water quality and source protection are important concerns in rural upland communities. Baseline assessments can identify water-safety concerns and inform locally appropriate monitoring and community extension activities. Objective: This study evaluated the microbiological quality and documented sourceprotection conditions of drinking water sources in Barangay Guinaban, Ocampo, Camarines Sur, Philippines, with emphasis on regulatory compliance and implications for local water-safety and extension planning. Methods: A descriptive secondary analysis was conducted using laboratory measurements and field observations documented in a 2026 master's thesis. Total and fecal coliform results from seven identified sampling sites, collected on April 2 and September 9, 2024, were examined against the microbial threshold of <1.1 most probable number (MPN)/100 mL specified in the source document. Results: Six sampling sites had measurements in April and six in September, with five sites represented on both dates. All 12 site-date observations for both total and fecal coliform exceeded the stated threshold. Among the five paired sites, three consistently recorded values exceeding 8.0 MPN/100 mL, while Z4-S1 increased from 4.6 to >8.0 MPN/100 mL and Z7-S1 shifted from 8.0 to >8.0 MPN/100 mL. An inconsistency was identified at the OCS sampling site, which was classified as compliant despite reported September measurements exceeding 1.1 MPN/100 mL. This discrepancy requires verification against the original laboratory certificate. Conclusion: The findings indicate microbiological water-quality concerns across the sampled sources and highlight the need for confirmatory laboratory testing, improved source protection, systematic sanitary inspections, and routine water-quality surveillance. Given the limited sampling periods and censored measurements, the results do not establish seasonal contamination patterns or causal relationships between sanitation conditions and microbial contamination.