Impact of urbanization on the water quality of the Uberaba River and tributaries

Abstract

This paper evaluated the quality of the water in Uberaba River and tributaries. Seven sites were sampled, in a 12-km under the influence of the urban area. The sampling site started upstream the raw-water catchment station, passing through the urban perimeter, upstream and downstream the discharge of the effluent treated by the Sewage Treatment Plant. Benthic macroinvertebrates were collected using a Surber net and, after identification, the indices of BMWP, diversity, equitability and dominance were calculated, besides functional group analysis. In each sampling site, it was analyzed microbiological and physicochemical parameters in order to identify possible domestic and/or industrial pollution sources. A rapid assessment protocol (RAP) was also applied, and land use and occupation aspects were mapped. The water collected in the furthest sampling site from the urban area and with vegetation in the surroundings, presented satisfactory quality, based in BMWP index. However, this quality dropped to very poor as the river water crossed the urban perimeter. The land use and occupation map showed a predominance of agriculture/pasture and urbanization. In addition, the presence of E. coli and the high levels recorded for some metals (principally cooper and cadmium), suggested contamination of the water with domestic and industrial effluents.