Since 2003, a full-scale dissolved air flotation (DAF) process has been operated by the Korea Water Resources Corporation (K-Water) in the Songjeon drinking water treatment plant (SWTP). The SWPT was designed with an adaptable operation mode so that it is able to produce safe and stable drinking water, even when the raw water is in very poor condition. The adaptable operation mode is able to buffer the dramatic change in the characteristics of the raw water. During the service period of 2003 to 2006, the SWTP has shown a constantly sound performance for the treatment of high turbid water (64-430 NTU), yielding a significantly low level of turbidity (DAF treated water, 0.15 similar to 1.16 NTU; anthracite filtered water, 0.02-0.09 NTU). In terms of the DAF process, this work focused on suggesting some practical solutions that would cope with several difficult problems that occurred in the DAF-based drinking water treatment plant. These problems included the unexpected high turbidity occurring during the heavy rainfall season, the scraper problem due to the shortage of feed water to the DAF process, and the increase of turbidity due to the use of powder activated carbon (PAC) prior to the DAF process. In addition, from a cost-effective perspective, the relationship between the recycle ratio and the operating cost was investigated in the DAF process under two different recycle ratio conditions.