The best approach to protect an aquifer on a regional scale is to use contamination prevention tools. The methods of estimating the vulnerability of groundwater allows to meet this need.

DRASTIC is a model that considers the main hydrological and geological factors with a potential impact on aquifer pollution. Its acronym stands for D—depth to groundwater, R—recharge rate, A—aquifer, S—soil, T—topography, I—vadose zone’s impact, and C—aquifer’s hydraulic conductivity (source

The results obtained for the DRASTIC indices thus suggest that approximately 25% of the aquifer in the Vaudreuil-Soulanges zone is vulnerable to contamination. The “buttes” of Saint-Lazare and Hudson have some of the highest vulnerability.