Monitoramento da qualidade da água da sub-bacia do Rio Tibiri e água potável do município de Santa Rita-PB.

Abstract

After the enactment of Water Law No. 9,433/1997, Brazil’s national water management framework gained favorable conditions that enabled the planning and implementation of actions aimed at improving the quality and availability of water in hydrographic basins. The Tibiri River Sub-basin requires socio-environmental balance, as it represents the main water source for the municipality of Santa Rita, Paraíba. For several years, this water body has suffered from external impacts such as pollutant discharges, siltation, and reduction of riparian vegetation, gradually distancing itself from its natural state, especially in riverside areas, and reaching more critical conditions during rainy periods. This research presents a physicochemical analysis of the water in the study area, covering both rainy and dry periods, in order to identify variations in parameters that may influence water treatment for human supply. The methodology was both qualitative and quantitative, using data from the year 2023. The records analyzed included municipal rainfall data, raw water parameters from samples collected at the intake dam, and treated water samples obtained from the outlet of the Water Treatment Plant (WTP). The analyses were carried out in accordance with SUDEMA/PB Directive No. 205 of March 23, 1988, CONAMA Resolution No. 357/2005, and the potability requirements established by Ordinance GM/MS No. 888/2021. The parameters of apparent color, turbidity, and pH were evaluated to assess the influence of rainfall on water quality degradation in both raw and treated water. The results indicated that during rainy periods, the water presented characteristics inconsistent with those expected for a Class 2 river, showing a very strong correlation between rainfall and the parameters of apparent color and turbidity. During dry periods, however, all requirements of CONAMA Resolution No. 357/2005 were met. The treated water remained within potability standards but exhibited a very strong correlation for apparent color and a strong correlation for pH when compared to raw water. Therefore, the findings are relevant for supporting local water management, guiding the development of improved management strategies, promoting transparency to the population, and contributing to the goals of Sustainable Development Goal 6 (Clean Water and Sanitation).