GROUNDWATER POLLUTION RISK AND VULNERABILITY MAP OF THE STATE OF SAO-PAULO, BRAZIL

Aiming to provide a global diagnosis of the actual threat of pollution to the most important aquifers of the State of Sao Paulo, Brasil, due to its intensive industrialization and agriculture, three government institutions - the Instituto Geologico (Geological Institute), the CETESB (Environmental Sanitary Technology Company) and the DAEE (Water and Electrical Energy Department) - carried out a regional survey to define the aquifers' vulnerability to pollution and for recording and ranking the potential contaminant sources. This paper describes the results of this survey, excluding the metropolitan area of the city of Sao Paulo. More than 500 industries were recorded and ranked according to their low, moderate or high potential contaminant load for impacting groundwater. Thirty - one aquifer units were defined and a 1:500.000 scale vulnerability map was produced. Critical areas were defined and recommended as being priority sites for the adoption of control measures.