Onsite or cluster wastewater system has been used to treat and dispose of relatively small volumes of wastewater, generally from individual or groups of dwellings and businesses. Especially onsite system is one of choices for remote sites such as islands. Centennial Technology built a packaged wastewater treatment plant at Wooeum island in Lake Shihwa. Packaged wastewater treatment plant manufactured by Centennial Technology is pre-engineered, modular wastewater treatment systems that bring advanced submerged membrane bioreactor (MBR) technology to municipal and industrial applications. Package plants can be quickly set up in virtually any location and feature scalable treatment capacity that can be quickly increased as demand grows. These plug-and-play systems outperform conventional treatment alternatives in all categories, offering superior quality effluent, reduced operating costs, smaller plant footprints, and more reliable performance.