Physico-chemical quality, microbial contamination, health risks, and community knowledge and perceptions of underground well water in commercial establishments of Kampala

Abstract

Underground wells are a major water source in Kampala but pose contamination and health risks due to limited community knowledge and poor sanitation. This study assessed the physico-chemical quality, microbial contamination, health risks, and community knowledge, perceptions, and practices regarding underground well water quality in commercial establishments in Kampala. A cross-sectional study was conducted among 302 respondents and 42 water samples from Kawempe, Central, and Makindye Divisions. Data collection followed standard analytical procedures, and results were compared with EAS and WHO water quality guidelines. Quantitative Microbial Risk Assessment (QMRA) based on E. coli data applied the Beta-Poisson model for risk estimation. Respondents (52% female, 48% male) were mainly aged 28-37 years; 48% had knowledge about underground water quality but 42.58% distrusted its safety. Education, gender, and age significantly influenced water-related knowledge and practices. Most physico-chemical parameters pH, hardness, EC, TDS, and iron fell within acceptable limits, except at Kisugu TC, Nsambya 1, and Nabukeera Plaza, where non-compliance occurred. Microbial results revealed high contamination with total coliforms and E. coli, especially in the Central Division, indicating fecal pollution and risk of waterborne diseases. Salmonellae and H. pylori were also detected in several sites. Regulatory compliance for E. coli and TC was low (≤24%), while Salmonellae showed the highest compliance (81%). QMRA findings showed the highest infection risks in the Central Division, with children more vulnerable than adults. The daily infection probabilities exceeded WHO benchmarks, indicating significant public health threats. While water from underground wells in Kampala is largely chemically safe, microbial contamination remains severe, posing serious health risks, particularly to children. The study underscores the urgent need for enhanced water quality monitoring, community education, sanitation improvements, and sustainable groundwater management policies.