The research reported in this paper looks into Quebec households’ response to groundwater quality degradation in terms of both the averting activities they undertake and the intensity of the costs they incur as a result. Of all the households suffering from water quality degradation problems, those facing water-related nuisances (odor, staining problems, and bad taste) are less inclined to take averting actions, and on average, they spend less to solve these problems than those suffering from water pollution by bacteria and minerals. Those on municipal water supply systems also tend to spend less on avoidance actions. Factors that determine households’ averting behavior are their geographic location, their closeness to farming activities, the environmental orientation of the head of the household and the presence of children under 18 years of age. The intensity of averting costs is influenced by the geographic location, the source of drinking water, the income, the educational attainment and the age of the head of the household as well as the number of children under 18 years of age.