Wong, JM, Farmerie, JE, and Wang, LK. (2019). Operation and performance of Clari-DAF® system for water purification. In: “Evolutionary Progress in Science, Technology, Engineering, Arts, and Mathematics (STEAM)”, Wang, Lawrence K. and Tsao, Hung-ping (editors). Volume 1, Number 8, August 2019; 63 pages. Lenox Institute Press, Newtonville, NY, 12128-0405, USA. No. STEAM-VOL1-NUM8-AUG2019; ISBN 978-0-9890870-3-2. —————- Xylem Water & Wastewater has provided Dissolved Air Flotation (DAF) systems to the municipal potable water treatment market since the early 1990s. This chapter will discuss the DAF process and the high-rate Clari-DAF® system design criteria. It will also present data from pilot studies and case studies of full-scale Clari-DAF® plants in operation showing expected performance through the system.