The business model bringing safe drinking water where public networks cannot reach

At 15, Brazilian entrepreneur Anna Luísa Beserra began working on a problem she knew from the semi-arid northeast: families stored rainwater in cisterns, but having water did not guarantee that it was safe to drink.

Her answer was Aqualuz, a system that disinfects water using direct sunlight, without electricity or chemicals. The idea became a business in 2015, when Beserra founded SDW For All to develop water-access and sanitation technologies for communities where conventional solutions face greater difficulties.

A decade later, the company reports operations in 16 Brazilian states, an international presence and tens of thousands of people reached. According to the company’s own figures, its projects reduced waterborne diseases by 92% among the populations served.

SDW’s growth did not rely solely on selling a product. The company expanded its portfolio with household and community systems that can use different water sources. It also built a process combining local diagnosis, installation, training, follow-up and impact measurement. Beserra says ensuring that a solution continues working after installation is the most difficult part of the business and what most distinguishes SDW from a conventional technology supplier.

The startup’s commercial answer was to separate the customer from the beneficiary. It works mainly with companies that finance impact programs and is seeking a larger role in government projects. Beserra said corporate programs cost about 150,000 Brazilian reais, or roughly $29,000, while larger projects can reach 2 million reais, about $385,000, under contracts lasting three or four years. The model was presented at the 2026 Startup Summit in Florianópolis as a possible reference for Paraguay’s continuing challenge of extending safe water access beyond the reach of existing networks.