Potability of Rainwater in the Eastern Amazon

Objective: This study aimed to assess the feasibility of using rainwater for human consumption as an alternative water supply in the Eastern Amazon, through a social technology for collection and treatment. Theoretical Framework: Despite the region's water abundance, access to potable water is limited, especially in isolated communities. Rainwater harvesting emerges as a viable alternative, provided its quality is rigorously evaluated. Method: The research was conducted in seven households on Ilha das Onças (Barcarena-PA) and one control unit in Belém. Water samples collected from rooftops and stored in cisterns were analyzed before and after treatment with sodium hypochlorite and filtration using activated carbon and polypropylene candles. Physical-chemical parameters (pH and electrical conductivity) were evaluated and compared with commercial brands, while microbiological parameters (coliforms) and trace metals were also analyzed. Results and Discussion: Rainwater had an average pH of 5.16 and conductivity of 9.1 μS·cm⁻¹; after treatment, these values slightly increased but remained below those found in commercial waters. Treatment reduced the microbiological load, although 53.8% of samples still showed total coliforms and 20.5% E. coli. In general, the samples did not show metal concentrations above the levels established by legislation. Research Implications: The results suggest that, with proper operation and maintenance, rainwater harvesting and treatment systems are a viable solution for water supply in Amazonian communities. Originality/Value: The study highlights a low-cost, sustainable alternative adapted to the region’s socio-environmental context for promoting health and well-being.