Santiago Chile has experienced a decade-long drought, and consequently, its water utility will begin rationing water. A four-tier alert system will implement restrictions depending on the current availability of water supply, culminating in rotating water cuts for up to 24 hours at a time for about 1.7 million customers. The interruptions to service could occur every 12 days to as frequently as every 4 days. 1
This will be a new experience for Santiago residents. Online information suggests that until now, the Santiago water utility has continuously supplied safe drinking water to its customers. Readers may have personal knowledge of life in Santiago and be able to comment with more authority, but my research suggests that while some residents may have used a faucet-mounted granular activated carbon filter, many or most residents in the city drank water straight from their tap with no treatment.
The planned interruptions to service mean that drinking the water directly from faucets will no longer be a good idea. It will put customers at risk of microbiological pathogens.
Why does interruption to service present a risk? When service is discontinued to an area of the water distribution system, the pipelines carrying water go from being under pressure to having no pressure. One of the primary means for protecting the safety of drinking water between the central treatment works and customers is by maintaining pressure in pipes. That way, if there is a leak, water flows out instead of dirt (which may include pathogens) flowing in. It’s not just theoretical; researchers have clearly documented the risks of service interruptions. 2
How does this discussion relate to the water box? Residents of Santiago are entering a new era in which household water treatment will need to be used in their homes if they are to drink water from the municipal system. The water box provides an excellent technology to address the concern about microbial pathogens: disinfection using UV light. Alternatively, people could boil their water (often inconvenient and it uses more energy) or use bottled water (also not convenient and certainly less environmentally desirable) or use another household water treatment method. A mature water box product could find a vast market in Santiago.
1 Information obtained from article “Chile announces unprecedented plan to ration water as drought enters 13th year,” via online edition of The Guardian (April 11, 2022).
2 Kumpel, E. & Nelson, K.L., 2013. “Comparing Microbial Water Quality in an Intermittent and Continuous Piped Water Supply.” Water Research, 47:14:5176; Kumpel, E. & Nelson, K.L., 2014. “Mechanisms Affecting Water Quality in an Intermittent Piped Water Supply.” Environmental Science & Technology, 48:5:2766.