AWWA MTC64623

The paper reviews the raw water quality, the finished water quality goals, the former treatment facilities, and the current treatment facilities at the City of Lake Forest, Illinois Water Treatment Plant (WTP). Then, the paper compares the current membrane treatment process with the former conventional treatment process in order to establish the pros and cons of the membrane treatment process. The City of Lake Forest had been operating a conventional WTP since the 1920s. When time came to upgrade the existing facilities in 2001, a membrane ultrafiltration (UF) process was selected. The City of Lake Forest has been operating the new 14 million gallons per day (mgd) UF WTP since April 30, 2004. The operators listed the pros and cons of the membrane treatment. Some engineering, contractual, and organizational considerations were added. Key discussion items included: finished water quality independent from raw water quality; high maintenance system; highly automated system; chemical usage; operation and maintenance cost; and, need for accepting risks. Low-pressure membrane filtration is becoming increasingly common in water treatment. For utilities like the City of Lake Forest, membrane technologies provide many unique advantages when rehabilitating an existing facility or building a new facility. However, selecting the right treatment process that addresses raw water quality, finished water goals, site constraints, and operation preferences is still the key to a successful water treatment project. Furthermore, utilities interested in low-pressure membrane filtration should be willing to accept the risk inherent in innovative technologies, assess and adjust their maintenance practices, and budget appropriate training for their operation staff and maintenance staff. Includes tables, figures.