Born in 1961, a graduate from the École Polytechnique and the École Nationale d'Administration, Jean-Michel Herrewyn started his career in 1986 as an engineer in the Avionics division of Thomson CSF. In 1991 he joined the Compagnie Générale de Chauffe (now Dalkia) as technical manager then general manager of the home automation subsidiary. In 1993 he became attaché to the managing director and in 1996 ran Dalkia's German subsidiary and later subsidiaries in Austria and Switzerland. At the beginning of 2000 he was also appointed general manager of Veolia Transport's German subsidiary, and also supervised developments in Austria and Switzerland. In 2000 he was appointed chairman of Valorec, a joint subsidiary of Dalkia and Veolia Environmental Services, created from the outsourcing of energy and waste management by Novartis plants in Basle (Switzerland). In March 2003 he joined Veolia Water as Managing Director of Veolia Water Solutions & Technologies. In December 2009 he was appointed Chief Executive Officer of Veolia Water, the Water Division of Veolia Environnement.