Impact of Tank Material on Water Quality in Household Water Storage Systems in Cochabamba, Bolivia

The importance of water as a mechanism for the spread of disease is well recognized. This study conducted household surveys and measured several physical, chemical, and microbial water quality indicators in 37 elevated storage tanks constructed of different materials (polyethylene, fiberglass, cement) located in a peri-urban community near Cochabamba, Bolivia. Results show that although there is no significant difference in physical and chemical water quality between polyethylene, fiberglass and cement water storage tanks there is a difference in microbial contamination as measured by E. Coli counts (p = 0.082). Evidence points toward elevated water temperatures that increase along the distribution system (from 10.6°C leaving the treatment plant) to within the black polyethylene storage tank (temperatures as high as 33.7°C) as the most significant factor in promoting bacterial growth. Results indicate that cleaning frequency may also contribute to microbial water quality (p = 0.102)