July 21, 2015
Our vision for Tres Santos is focused on health, serenity and a reconnection with nature. So to make that vision complete, we knew that Tres Santos had to be as self-sustaining as possible.
One of the biggest issues we had to address in our plan for self-sustainment was finding a water source that would have low ecological and community impact. Because of existing demands on the current water infrastructure we didn’t want to rely on the local water supply as a long-term solution. Instead, we looked to other seaside towns for a solution and determined the best long-term strategy was to build a land-based Tres Santos desalination plant, scheduled for completion in early 2016. (As an interim measure, we’ve made arrangements with the municipality to temporarily bring in additional water while we complete the plant. Read more about that here.)
How It Works
The desalination process typically begins by either taking water from the ocean or from wells under the ground. However, the direct-from-ocean approach has many drawbacks, including potential harm to marine life, which can become stuck in the collection system. So we decided instead to use the well approach, pulling the saltwater from beneath our building site. (We are not tapping into the nearby Punta Lobos fresh water aquifer.)
Electric pumps will draw the water out, and then the water will run through filters to remove the brine (salt) and capture the now-fresh water. Some desalination takes place naturally in the ground, so the process will require very little energy compared with a direct-from-ocean process.
Another important decision we had to make was what to do with the brine after it’s been removed from the water. Many desalination plants return it to the ocean, but over time, this can disrupt the natural salt and mineral ratios in the water. We chose a different method, returning the brine to the ground below our well, which is safer for the ecosystem and much less disruptive to marine life.
The residents of Tres Santos will use the desalinated water for drinking, dishwashing, showering and other fresh water needs. The Town Farm community will also use the desalinated water to grow fruits and vegetables they can sell in Todos Santos.
Stay tuned for updates on the progress of our Tres Santos desalination plant.