AWWA WQTC69241

The Three Rivers Water Filtration Plant at Fort Wayne, Indiana, has a long history of competent operation and successful production of high quality finished water. Chemical feed control had been challenging because of rapid and often dramatic changes in raw water quality (i.e., the raw turbidity varies from 2 to 500 NTU and the total hardness varies from 100 to 450 mg/L as CaCO₃). This paper discusses a computer model that analyzes real time raw water quality that has recently been implemented at the Three Rivers WTP, and has helped the operators to more accurately predict the required chemical feed rate changes. The operators have also used this model to optimize the plant's chemical feeds, resulting in improved effluent turbidity and reduced chemical cost. Includes tables, figures.