19 November 2017The Alsatian aquifer is the largest aquifer in Western Europe and supplies groundwater for almost all households in Alsace, without any treatment in most areas. The main objective of this paper is to compare the willingness-to-pay of households living in polluted areas with those having access to preserved quality. Results are presented of a contingent-valuation study of the Alsatian aquifer: On the basis of a representative sample of households, directly interviewed on 10 different sites, the determinants of the preservation value of groundwater quality are estimated using two different methods of payment (referendum and open-ended method) and two versions of a questionnaire differing by the reliability of the proposed preservation programme. It was found that households living in polluted areas have a greater willingness-to-pay for a hypothetical programme of preservation compared to the other households. Also, in contrast with previous studies on groundwater it was found that neither the reliability of the programme nor knowledge of the water bill significantly affected the mean willingness-to-pay, (C) 1998 Academic Press.