Source-to-tap assessment of microbial and physicochemical quality of drinking water in Yirga Chafe Town, Gedeo Zone, Ethiopia

Abstract

This study evaluated the physicochemical and microbiological quality of the municipal drinking water supply in Yirga Chafe Town, Southern Ethiopia, across four operational stages (3 primary sources, 3 storage reservoirs, 3 community taps, and 3 household connections). A physical water samples (n=3 physical triplicates per node) were analyzed for ten water-quality parameters/indicators. Physical parameters, including turbidity (0.0‐1.23 NTU), electrical conductivity (13.5‐24.5 μS/cm), nitrate (0.04‐0.05 mg/L), and iron (0.01‐0.04 mg/L), complied with World Health Organization (WHO) and Ethiopian national guidelines. However, slight pH suppressions (6.2‐6.4) were observed at select upstream nodes. Free significantly along the distribution pipeline, dropping from reservoir levels (0.15‐0.25 mg/L) to 0.03±0.00 mg/L at household connections, falling well below the WHO minimum threshold (0.2 mg/L). Fecal coliforms were absent at source and reservoir nodes (0.00 CFU/100 mL) but increased downstream, reaching 2.00 CFU/100 mL at community taps and 11.4 ± 1.66 CFU/100 mL at household connections. Total coliforms throughout the network indicate downstream microbial deterioration due to inadequate chlorine disinfection. This highlights the need for improved routine monitoring and stronger residual chlorine protection along the distribution system.

The authors' abstract, as published at the source. Journal of Environmental Science and Health Part A, 2026 · DOI ↗