Trihalomethane Levels in Tap Water Samples Obtained from Kinki Area in Japan.

Trihalomethane levels and parameters (pH, temperature, KMnO4-consumed values and residual chlorine) in tap water samples obtained from Kinki area in Japan were measured. Furthermore, we studied the effect of the addition of activated carbon during the preparation process on the trihalomethane levels in tap water. Sixty eight samples of tap water were collected from the domestic water supply of Hyogo, Osaka, Kyoto and Nara prefectures. No significant correlation was found between the trihalomethane levels and parameters. On the other hand, the addition of activated carbon to tap water significantly decreased the trihalomethane levels.