Groundwater Vulnerability Card: the Vulnerability Scale

The map of the vulnerability of the groundwater of the Flemish Region can be defined as a map of the level of risk of contamination of groundwater in the upper water layer by substances that penetrate from the soil into the ground, only taking into account static parameters. This map can later serve as a basis for a more detailed map, which can also include dynamic and hydrochemical factors. Where, however, the top recoverable aquifer is naturally silencing (>> The vulnerability scale Based on the above factors, a vulnerability scale has been drawn up. Five vulnerability degrees are defined, each shown by its own color on the map. The vulnerability scale is as follows: • Extremely vulnerable (red on map): * A.a.1.: Chalk, limestone, sandstone, uncoated marl, with an unsaturated zone of 10 m or less than 10 m; *B.a.1.: Uncoated gravel with an unsaturated area of 10 m or less than 10 m • Very vulnerable (orange on map): *A.a.2.: Chalk, limestone, sandstone, marl, uncoated, with an unsaturated zone exceeding 10 m; *B.a.2.: Uncoated gravel with an unsaturated zone exceeding 10 m; *C.a.1.: Uncoated sand with an unsaturated zone of 10 m or less than 10 m • Vulnerable (yellow on map): *A.b.: Chalk, limestone, sandstone, marl, with a loamy coating; *B.b.: Gravel, with a limp coating; *C.a.2.: Sand, uncoated, with an unsaturated zone of more than 10 m. • Moderately vulnerable (light green on map): *A.c.: Chalk, limestone, sandstone, marl, with a clay coating; *B.c.: Gravel with a clay coating; *C.b.: Sand with a limp coating; *D.a.1.: Uncoated clay or clay-containing sand with an unsaturated area of 10 m or less than 10 m; *D.a.2.: Clay or clay-containing sand without coating with an unsaturated area of more than 10 m. • Little vulnerable (dark green on map): *C.c.: Sand with a clayy coating; *D.b.: Clay-containing or clay-containing sand with a loamy coating; *D.c.: Clay-containing or clay-containing sand with a clayy coating.