The disinfection of water intended for human consumption is one of the major public health advances of the 20th century. However, the reaction of chlorine with soluble organic matter in water produces undesirable chlorination byproducts (CBPs). Studies show an association between the risk of bladder cancer in men (BCM) and exposure to CSPs, estimated by the concentration of trihalomethanes (THMs) in treated water. A 2011 meta-analysis proposes a concentration-response relationship (CRR). The aim of our study is to estimate current and past exposure to THMs among people residing in France, as well as the associated health impacts. Current exposure of the French population was estimated based on THM analyses from health monitoring (2005–2011). Exposure to THMs between 1960 and 2000 was modeled. The current average exposure of the French population is estimated at 11.7 μg/L, compared to 17.3 μg/L in the past. The population supplied with surface water is half as exposed as in the past, but remains twice as exposed as the population supplied with groundwater. A wide geographic disparity in exposure is observed. Assuming the validity of the CRF, 18% of HCV cases would be attributable to SPCs (1,600 [500; 2,700] cases per year). If exposure remains unchanged, this figure would be 16% in the future. Capping the highest exposure values would have a negligible effect on the health impact.