Recife, capital of Pernambuco State located in northeastern Brazil, has been undergoing an accelerated urbanization process osince the 1970’s, especially in its coast. Therefore, the demand for fresh water has increased severely and in order to satisfy this need groundwater is one of the most exploited resources. The risk of salinization in the regional aquifers by saltwater intrusion has also increased. The coastal region of Recife is a plain area, its southern area lies next to an estuarine zone and it has high population density together with high concentration of wells. The high water pumping rates combined with the reduction of recharge rates make this area vulnerable to salinization problems.