No abstract

Abstract Safe water storage is critical to preserve water quality, especially when intermittent piped drinking water supply creates a need for household storage. This study characterized household storage practices and stored water quality in 94 households (N = 94) among four peri-urban neighborhoods in Arraiján, Panama with varying degrees of supply intermittency. We found that 18 (19.1%) households stored drinking water in unsafe containers. Forty-four (47%) samples of household stored drinking water had residual chlorine levels <0.2 mg/L. While 33 (35.1%) samples were positive for total coliform bacteria, only 23 (24.4%) had >10 most probable number (MPN)/100 mL total coliform bacteria. Eight (44%) samples were positive for Escherichia coli, whereas only one (1.3%) sample from the safe containers was positive. Twenty-nine (30.9%) samples had >500 MPN/mL heterotrophic plate count bacteria. These findings suggest that longer supply interruptions were associated with longer storage times and lower chlorine residual, which were associated with higher concentrations of indicator bacteria. This is one of the first studies in the Central-American region to show an association between the lack of turnover (replacement with fresh water) and greater contamination during household water storage. Thus, when drinking water supply is not completely continuous and household storage is required, decreasing the time between supply periods can facilitate safer water storage. Public awareness and education are also recommended to increase hygiene practices during water collection and storage.

Intermittent piped water supply is common in low- and middle-income countries and is inconvenient for users, particularly when supply schedules are unreliable. In this study, supply schedules and operational challenges were characterized in intermittent areas of the Arraiján, Panama distribution network based on one year of pressure and flow monitoring in four study zones, analysis of three years of pipe break data, and observations of system operation. Service quality was found to vary among users and supply schedules were often irregular and unpredictable. Direct causes of unanticipated supply outages included pump failures, chronic pipe breaks in specific parts of the system, transmission main breaks, irregular valve operations, and treatment plant outages. The extent and duration of these outages were often increased by high rates of water loss, insufficient storage capacity, and difficulty detecting and resolving infrastructure failures. Factors associated with intermittent supply, such as intermittent pumping, appeared to be associated with a higher frequency of pipe breaks. However, the analysis did not indicate a strong general correlation between intermittent supply and pipe breaks. Pressure and flow monitoring in intermittent supply areas, similar to that undertaken in this study, could be a valuable tool to improve regular operations as well as longer-term planning and prioritization of system improvements. Water loss reduction and adequate distribution storage capacity could also mitigate the effects of operational failures. Investments in monitoring and data analysis have the potential to improve the reliability of intermittent supply in cases where continuous supply is not immediately feasible.

No abstract