Groundwater usage

• in NL about 65% of drinking water comes from groundwater
• quality of groundwater for drinking is better and more constant and is extracted far beneath surface where no bacteria can live
• groundwater contains high amounts of iron and low amounts of oxygen so it has to be aerated and filtered before it is drinkable
• average water use is 135 l per person per day (about 50 m3)
• industry uses about 90 l per person per day (525 million m3 per year)
• water quality of groundwater determines whether extraction is possible
• extracted groundwater often compensated with surface water
• excessive use of fertilizer and pesticide in agriculture lead to leaching of nitrogen and phosphorous into groundwater, polluting groundwater
• in NL 6500 l per person per day used for food production/agriculture
• groundwater has significant influence on crop yield

  • optimal depth is about 1 – 1.20 meters
• natural areas want high levels of groundwater to stimulate diverse plant growth but also maintaining enough air in soil

  • plants extract water from topsoil leading to lower soil moisture contents in root zone
  • replenished by precipitation or capillary rise from groundwater
  • wet vegetation types require stable and shallow groundwater tables
• groundwater tables affects main physical, chemical and biological processes in soil
• main environmental factors that determine vegetation types: groundwater levels, nutrient status, acidity, salt concentration
• high salinity concentrations in root zone make it hard for plants to extract enough water from soil to meet their transpiration demands
• groundwater pollution due to different compounds from different sources

  • agriculture is high source of contamination (high amount of nutrients)
  • industry dumps heavy metals, solvent and organic micropollutants
• groundwater flows from high areas to low areas

  • increase in water pH
  • increase in nutrient amount
• pollution can stay in groundwater for decades/centuries
• limited amount of hanging water (water held in soil against gravity) determines which natural vegetation and agricultural crops are possible