In many countries around the world, groundwater plays a crucial contribution to the water supply for millions of people and livestock, as well through the irrigation of agricultural land for food production. Climate change, rising sea levels, contamination by microplastics, hormones, slurry and wastewater from industry, plus an exponentially growing world population present global water suppliers with an almost unsolvable challenge, which is to provide clean affordable groundwater in sufficient quantity as sustainably as possible.