A large quantity of irrigation water is necessary for 'J' island in Korea to sustain its main industry of agriculture despite insufficient water resources. Therefore, the local government has decided to develop the wastewater reclamation system. Secondary effluent from 'J' domestic wastewater treatment plant ('J' DWWTP) was selected for this purpose. The treated water quality was required to satisfy the drinking water standard because the irrigation water would eventually end up in their sole water source of groundwater. An integrated membrane system (IMS) had been installed and operated for 6 months. Conductivity and disinfection by-product (DBP) were the criteria parameters for the process screening. After careful investigation, IMS (20 m(3)xd(-1)) was constructed with microfiltration (MF) and reverse osmosis (RO). MF was selected as pre-treatment because sand filtration was not effective in removal of small-sized particles, while RO was selected due to high conductivity in the effluent of 'J' DWWTP. According to the operational results, IMS showed the stable performance. The treated water quality satisfied the drinking water standards and was comparable to those of groundwater on 'J' island.