• Protecting family drinking water in rural Alaska: improved water management in homes without running water

      Laderach, Shawna R. (2006-12)
      The objective of this study was to investigate and make recommendations for improved in-home water management in an underserved rural Alaskan community without piped water. The main focus of the study is point-of-use disinfection. A model was developed based on experiments to predict the chlorine decay over time and the necessary chlorine dosage for waters used in the pilot community so that sufficient chlorine residual would remain during storage. TOC concentration, initial chlorination level, reduced iron and temperature were major factors impacting the chlorine consumption. Safe free chlorine levels of between 0.2 mg/L and 4.0 mg/L could be achieved in a reasonable time and maintained for typical storage times, while avoiding unpleasant taste. A taste test in the community showed that levels of 1 mg/L or less could not be distinguished by most people and were acceptable for drinking. Storage and hand washing are likely major components of preventing microbial contamination. It was determined that closed containers do not slow the loss of disinfectant from evaporation. Thorough hand washing for at least one minute using soap and running water is recommended, since this was the most effective method to remove coliform bacteria from hands.