The utilization of wastewater is big business for Brazil's big cities, which could solve their water shortage problems, Marcelo Zanini, director of the water treatment firm Biosistemas, told Tierramérica. Supplying one cubic meter of water and the services for its drainage cost 8.3 dollars in Sao Paulo, but existing technologies permit its reutilization for one-third that price, he said.

Channeling water from a source 130 km to handle the shortage in the Sao Paulo metropolitan region could be put off 15 years if the city treated its wastewater for reuse — with financial, energy and environmental benefits, said Zanini.

Recycling water through biological processes and membranes offers “infinite” opportunities, given that now just a quarter of the 130,000 companies in Sao Paulo state do so, he added.