Following the emergency response to deal with contaminated drinking water in San Salvador, IHE Delft lecturer, Gerald Corzo Perez, has been telling us about the mission.
“The emergency happened due to a record low flow in an early dry season” says Corzo, a civil engineer and expert in hydroinformatics. “But this year it came early and the system couldn’t cope. The chemicals from this bloom weren’t toxic,” Corzo added, “but they make drinking water smell and taste unpalatable.”
Corzo and his collaborators Luuk Rietveld from TU Delft, and Hector Angarita of the Stokholm Environment Institute (SEI) were able to rapidly assess the water systems flowing into the San Salvador treatment plant. Building models based on 40 years of water discharge data they identified the sources of the problem and worked out the best points at which to tackle it. Their findings showed that a combination of low water levels, agricultural chemicals and hydroelectric power generation further upstream had contributed to high rates of algal growth.
“The solution in the short-term is to use activated carbon to effectively filter out the chemicals from the algae, and to re-schedule the releases from the upstream reservoir,” says Corzo. “In the longer term, with climate change leading to more and earlier droughts, the solution will be to think on a better IWRM strategy, from nature based solutions, to the improvement of the water monitoring and expand the capacity of the water treatment plant to better deal with blooms as they arise.”
IHE Delft, TU Delft and SEI will continue to work with the El Salvador government in the coming months, both to monitor the efforts to deal with the latest bloom and to assist in preparing for the future.