Situation of ground water
Ground water is rainwater that has seeped into the substrate. It is important for the production of drinking water and prevents agricultural and wildlife areas from drying out. The quality of ground water is good in 60% of the water bodies. Elevated nitrate concentrations is a problem. The quantity of ground water is generally good, although locally some wildlife areas suffer from a lowered ground water table.
Ground water that is very deep in the earth moves very slowly (a few metres a year). As it moves, the ground water is naturally purified – pollutants and harmful bacteria are removed. This creates water of a good quality that is suitable for preparation as drinking water.
Quality standards for ground water
There are quality standards that pertain to ground water as well. These standards are recorded in the Decree on Quality Standards and Monitoring for Water (2009, in Dutch). They are based on the Water Framework Directive (in Dutch) and the Ground Water Directive. The Ground Water Directive requires member states of the European Union (EU) to guarantee the chemical quality of the ground water.