I have been requested by a colleague to provide a list of references on the isotopic composition of water percolating through landfill sites, and in particular on its tritium content. I would appreciate if the Isogeochem friends would help me by providing the title of recent publications in that field. Roberto Gonfiantini Prof. Roberto Gonfiantini Istituto di Geoscienze e Georisorse Institute of Geosciences and Georesources Area della Ricerca del CNR Via G. Moruzzi, 1 I-56124 Pisa Italy Phone +39-050-315-2358 e-mail [log in to unmask]