Water and sediment quality assessment - Ribeirão do Laranjal watershed

The sediment and water of a river can be impacted by the development of modern society. The sediment is responsible for the transport, release and accumulation of toxic compounds and nutrients and can alter the quality of the water. Thus, the objective of this study was to analyze the water and sediment quality of Laranjal stream, located in Laranjal Paulista (Sao Paulo, Brazil). Water and sediment samples were collected in the rainy and dry seasons of the year 2012. The analysis indicated that the sediment presented high content of Cd, Ni, Pb, Cu and Cr. The toxicity test indicated that the river mouth was distinct from the spring and the middle course and the electrical conductivity of the water was high at the sampling point within the urban mesh of Laranjal Paulista. Considering the use and occupation of the Laranjal stream watershed, the rural mes h (dominated by pasture and plantation) influences predominantly the quality of water and sediments.