Simulating distribution of trihalomethane in tap water in the area receiving a combination of advanced treated water and conventionally treated different source water: 1998, 1999 and 2002 data on Osaka Prefecture and its surrounding cities, Japan.

Empirical equations for explaining trihalomethane (THM) distribution were established based on data on tap water in Osaka City before and after starting the advanced treatment and were represented by the following equations for bromodichloromethane (S(1)), dibromochloromethane (S(2)) and bromoform distribution factors (S(3)) as a function of chloroform distribution factor (S(0)), respectively: S(1) = -0.97S(0)(2) + 0.75S(0) + 0.19 (regression coefficient: r = 0.71), S(2) = 0.13S (0) (2) -0.76S(0) + 0.51 (r = 0.98) and S(3) = 0.83S(0)(2) -0.99S(0) + 0.30 (r = 0.97). Further, the derived equations were verified by THMs data of Osaka Prefecture and its surrounding cities (except for Osaka City), receiving a combination of advanced treated water and conventionally treated different source water.