Aging Infrastructure and Water Safety: Comparative Insights from Multi-Pollutant Pipeline Hotspots in Birnin Kudu, Jigawa State, Nigeria

Drinking water safety in low- and middle-income countries is increasingly threatened by post-treatment contamination within deteriorating distribution systems. This study assessed how pipeline integrity influences water quality and public health in Birnin-Kudu, Nigeria. Over 12 months, 180 samples were collected from treatment plant outlets, intact pipelines, and damaged pipelines and analyzed for physicochemical, nutrient, metal, and microbial parameters using geo-accumulation (I_geo), contamination (CF), and health risk (HQ, HI) indices. Though water was of good quality at the treatment outlets and met WHO standards, the quality deteriorated sharply at households served by damaged pipelines; for instance, turbidity, 9.4 NTU; nitrate, 14.9 mg/L; ammonia, 0.57 mg/L; copper, 0.26 mg/L; and coliforms, 134 CFU/100 mL were all elevated. Pollution indices indicated localized hotspots and significant health risks in HQ > 2.5 and HI > 1. Multivariate analysis further identified that deterioration of pipes generates synergistic multi-pollutant clusters that combine physical, chemical, and microbial contaminants beyond safe limits. This study, therefore, gives the first quantitative evidence from sub-Saharan Africa of the linkage of pipeline decay with compound contamination and health hazards and underlines the imperative for predictive maintenance, monitoring of hotspots, and infrastructure rehabilitation toward the safeguarding of global drinking water quality.