Assessment of Water Quality of the Sao Goncalo River in the Urban Section of Sao Domingos do Norte-Es

The Water Quality Index (WQI) gathers information on physical-chemical and bacteriological parameters. This article analyzed, monthly for one year, water samples collected at the source and downstream of the São Gonçalo River in the municipality of São Domingos do Norte, at Espírito Santo. The average accumulated precipitation of the month that preceded the collection was grouped into dry and rainy periods. Precipitation data allowed classification into dry and rainy periods (p-value 0.0084). The WQI values were calculated and statistically evaluated regarding the collection point and precipitation (p-value 0.0125). In dry periods, the WQI presented lower values than in rainy periods. It was observed that at the source of the river, the WQI value was higher than downstream from the urban center due to anthropological action. Finally, the research allowed the identification of the temporal and spatial variation of the water body resulting from contamination by sewage contribution.