The use of shallow geothermal energy (SGE) systems to acclimatize buildings has increased exponentially in the Netherlands and worldwide. In certain areas, SGE systems are constructed in aquifers also used for drinking water supply raising the question of potential groundwater quality impact. Impacts of Shallow Geothermal Energy on Groundwater Quality provides a hydrochemical and geomicrobial overview of the effects of ground source heat pumps and aquifer thermal energy storage. The area is investigated with field and laboratory experiments, and reactive transport models, showing that shallow geothermal energy systems can influence groundwater quality in a number of ways. Most prominent in open ground source heating systems operating at low temperature (