Contamination of water-bearing strata is, in contrast to the contamination of surface waters, for most people not noticeable. However this does not lead, at least in Germany, to reduced awareness about the problem, as drinking water and groundwater are closely connected in the public's mind. The cleanup of contaminated groundwater is generally aimed at a negligibly low or tolerable remaining risk for the subjects of the protection. The goals of the cleanup should always be considered in the light of the appropriateness of the time and effort involved and the environmental balance of cleanup measures. Otherwise there is the danger that technical environmental protection however well meant is directed against the environment, because the associated use of resources is greater than that for the protection or regeneration at which it is targeted. Different cleanup concepts are represented in the order of decreasing intensity of the technical measures.