Sustainable synergies for the subsurface combining groundwater energy with remediation: an illustration with 2 cases

In the last decade the policy on largely contaminated areas in the Netherlands has moved to groundwater and risk management. Parallel to this development the application of Heat Cold Storage (HCS) in groundwater has increased significantly as a result of the shift to more sustainable energy sources. Currently there are about 1.000 systems, and this is expected to increase to 20.000 in 2025. HCS initiatives are often used in dynamic areas (inner cities) where groundwater contaminants are also found. In a strict interpretation the Dutch Soil Protection Law prohibits the additional movement of contaminants and therefore the application of HCS in or near contaminants. But higher environmental goals at a more holistic level are also regarded nowadays, and what used to be a bottleneck is regarded as a perfect opportunity to combine the remediation of contaminated areas with sustainable energy1. Sensible use of the subsoil can lead to profit, and can also be a perfect means to protect and improve soil and groundwater quality. HCS systems can be used to contain, control or sustainably remediate groundwater. In this abstract two different, real life approaches are illustrated for the combination and interactions of Heat Cold Storage and Remediation. They all illustrate the shift towards sustainable use of groundwater, a means of improving groundwater quality.