Use of a multiple regression model for predicting trihalomethane formation

For many years the water supply system of Athens in Greece has been disinfected mainly by chlorination. A consequence of chlorination is the formation of trihalomethanes (THMs). A survey was conducted to determine their levels in the Athens water supply system over a period of time. A multiple regression model for THM formation was generated for predicting THMs in the finished water leaving the plant using the field sampling of the Galatsi Treatment Plant (GTP) of Athens with respect to temperature, pH, chlorine dose, bromide and chlorophyll a. In general, this model was found to give acceptable fits. Overall 82% of the predicted values were within ±20% of the measured values.