Aristides Lamproulis believed that the efficient and sustainable solution and promotion of serious economic and institutional problems faced by the Greek Municipal Water and Sewerage Companies could be achieved only by a common Organization and network.
25 Mayors, presidents of D.E.Y.A.s accepted and endorsed Aristides Lamproulis' views and the Association of Municipal Water and Sewerage Companies became a reality in 1989 having 25 D.E.Y.A.s members.
The Hellenic Association of Municipal Enterprises for Water Supply and Sewerage (E.D.E.Y.A.) started its operation in January of 1990.
Since then 117 D.E.Y.A.s all over Greece have joined E.D.E.Y.A., enhancing its role within the greek water sector.The members of E.D.E.Y.A. provide water, sewerage and teleheating services to 5 million citizens i.e. the half of the greek population.