Reality or myth: “Advanced wastewater treatment technologies cannot be cost competitive with conventional treatment processes”

With shortage of water becoming a major concern in many areas, use of recycled water is a necessity for a growing number of municipalities. This paper describes a case study in which two alternatives were considered for upgrading an existing wastewater treatment plant with the goal of producing recycled water. The first alternative consisted of conventional secondary and tertiary unit processes while the second alternative included the advanced treatment technology of membrane bioreactor (MBR). Also, two alternatives were evaluated for disinfection of recycled water; chlorine gas and UV system. The more advanced treatment technologies (MBR + UV), which produce the higher quality recycled water, resulted in higher cost. The paper discusses the design and project execution approaches as how the more expensive advanced treatment processes were made cost competitive with the conventional treatment processes.