HCOV_0300, Tree Aquitard Prevention Area

Flanders is made up of an alternation of aquifers (sand, gravel, chalk, solid rock, ...) and regionally occurring non-aquifers (e.g. clay). The sequence of these aquifers and aquitards has its own coding in Flanders: the Hydrogeological Coding of the Subsurface of Flanders (HCOV-coding). The HCOV coding is made up of hydrogeological main, sub and base units. The main unit groups a sequence of geological layers that have broadly the same hydrogeological properties and thus form a single whole. This hydrogeological main unit corresponds to the very poorly permeable clay layer of the Tree Formation. This is a well-localized and homogeneous sealing layer. The lower clay parts of the Formation of Eigenbilzen are also included in this main unit, as they are very difficult to distinguish hydrogeologically from the Formation of Boom.