Water Quality Degradation after Water Storage at Household Level in a Piped Water System in Rural Guatemala

Abstract

In response to a rural community’s concern regarding diarrheal disease, particularly among children, a field assessment was performed to determine the concentration of 4 classes of indicator bacteria: aerobic bacteria, total coliform, fecal coliform and Escherichia coli. Matched supply tap and storage container samples were taken from 28 households; two additional samples were taken at the main storage tank. Total and free chlorine concentration was also determined for each sample. While nearly all samples taken from household taps were near or below limits of detection, samples from storage containers all showed high densities of indicator bacteria and one was positive for Salmonella. All chlorine measurements indicated concentrations of < 0.5 ppm. These data suggest that while the source well water shows indicator bacteria concentrations at or below limits of detection, drinking water becomes significantly more hazardous while in storage containers at the household level, and this reflects insufficient chlorination. An uninterrupted and adequately chlorinated water supply system is planned to eliminate the need for drinking water storage at the household level.