HCOV_1000, Prevention Area of the Paleocene Aquifer System

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 is mainly formed by the various successive aquifers belonging to the Landen Group (Formations of Tienen and Hannut) and the Formations of Heers and Opglabbeek. This is a highly heterogeneous water-carrying package, in which several less permeable clay layers are present.