The problem of haloforms in drinking water treatment has made necessary to investigate new treatment methods capable of reducing the amount of halo-compounds formed when chlorination must be maitained in particular for disinfection, in the network. In laboratory test, as well as in pilot and industrial studies, different treatment lines have been tested. The measurement of precursorsand humic acids, and the use of chlorine as a decomplexing agent for humic matter give the possibility to determine the kinetic conditions for haloforms appearance during potable water treatment and to define a treatment line avoiding halogenous compound formation.