Manganese excess worries authorities and experts
Nova Sintra City, December 26, 2025 (Bravanews) - The water desalination project, seen as the "salvation" for water scarcity on the island of Brava, faces an unexpected obstacle that lies in the composition of the soil itself. Although the extraction technology is operational, recent laboratory analyses have confirmed that the water produced has magnesium levels significantly above the standards recommended for continuous human consumption.
According to a source close to the technicians, the problem is not with the machine, but with the source. The water is collected in areas where the geology is made up of a complex mixture of limestone and volcanic rocks.
According to this source, these rocks are naturally rich in minerals. When the water passes through these underground layers before reaching the wells, it "washes" the minerals out of the rocks, resulting in a high concentration. In the specific case of this region, the interaction between the limestone and the volcanic substrate has created a natural deposit that saturates the water with manganese.
It's important to demystify the nature of this mineral. Manganese is essentially an ally of the human body. It performs vital functions, such as fixing calcium in bones, helping muscles contract and relax, and assisting in the regulation of nerve impulses.
Manganese is essentially an ally of the human body.
However, the popular saying "the difference between medicine and poison is the dose" applies here. In excessive amounts, manganese can cause health problems, including gastrointestinal disorders (laxative effect), kidney problems in vulnerable people and electrolyte imbalances in the body.
The technical team responsible for the project is already implementing contingency measures. The immediate solution, until the technical problem is resolved definitively, is to change the extraction point.
"We are working to extract water from the back side of Furna. This area has a different mineralogical composition, which allows us to supply the population with more balanced water for the time being," explained one of the technicians involved in the project.
In the long term, the solution will not just be to change the catchment area, but to adapt the treatment plant. A manganese reduction project is already being designed, which could include specific filters to capture manganese ions, adjusting the membranes to selectively filter out excess heavy minerals and combining the desalinated water with other sources to dilute the concentration of the mineral.
The authorities guarantee that the water distributed will undergo rigorous testing before it reaches the taps, ensuring that manganese goes from being a concern to just another beneficial nutrient in the population's diet.
