GROUNDWATER CONTAMINATION RISK MAPPING IN URBAN WATERSHED

Abstract Groundwater contamination cause different risks to society, promoting rise of the disease’s cases, in addition to reduce the hydric disponible and to degrade the aquifers, that are strategic reservoir to hydric sustainability of society. Therefore, this study was aimed to applies the groundwater contamination risk index - IRCAS, identifying they efficiency in indication/prediction of water contamination in a urban watershed on Fortaleza City/Brazil. For this, we applied the vulnerability aquifer model GOD to set natural susceptibility and to match environment sanitation index - ISA for to produce the IRCAS. For identify the efficiency this model, we accomplish 2 field campaign, one at the end of the rainy season (July), and other in dry season (November), to analyzed physics and chemistry parameters of groundwater collected of the wells. The major contamination was caused to nitrate, that presented 53 and 46% of the sample out of potability standard on rainy and dry period, respectively. The variance analyses - ANOVA report model efficiency of 61 and 54% of explication of the nitrate contamination variance for on rainy and dry period, respectively.