Integrated analysis of water quality from two rivers used for public supply in southern BrazilAbstract:
Aim This study aimed to evaluate the water quality of streams that are used for public supply, through an integrated analysis using a biotic index, as well as physicochemical and microbiological parameters.
Methods The data were obtained monthly, from November 2014 to April 2015, at eight locations in two rivers in the south of Brazil. The landscape is predominantly rural, with the occurrence of small reforested areas, as well as yerba mate and grape cultivations. Macroinvertebrate samples were collected monthly using a Surber sampler. Water temperature and dissolved oxygen concentration were measured in the field using a portable oximeter. The following parameters were measured in the laboratory: pH, Turbidity, BOD, Conductivity and Nitrate.
Results The evaluation carried out in the rivers revealed good water quality, but some sample sites presented reduced water quality. The waters of the Leãozinho River were classified as doubtful at site 1 and as good at sites 2, 3 and 4. Ligeirinho River presented an acceptable rating at sites 1 and 4 and was classified as good at sites 2 and 3. The BMWP’ index was significantly correlated with the abundance of macroinvertebrates, EPT richness and BOD. The abundance and richness of macroinvertebrates in Leãozinho and Ligeirinho Rivers were associated with the physical, chemical and microbiological parameters.
Conclusion This study reinforces the importance of biomonitoring in the evaluation of water quality for human consumption, considering that environmental management and monitoring practices should integrate physicochemical, microbiological and biological parameters.
Keywords: macroinvertebrates; BMWP’ index; physicochemical parameters; human consumption