Water Management Water Environment Management Master Plan Water Use Charge Whole Effluent Toxicity Management System Riparian buffer zone designation system This is a system that restricts the construction of restaurants, accommodation, spas, factories, and warehouses by establishing a certain section of a river as a buffer zone connecting the aquatic ecosystem and the terrestrial ecosystem for the purpose of securing a healthy aquatic ecosystem and clean water, and designating a Riparian Buffer Zone to form a Riparian Buffer Forest after buying lands near the waterside one by one, through agreements with residents. For the Han River watershed, 255 km2 adjacent to Paldonghosu, Namhan River, Bukhan River, and Kyoungan stream was first designated as a Riparian Zone in September 1999. Three successive changes have reduced its size to 191.3 km2. For the Nakdong River, Geum River, and Yeongsan River watershed, major dams and the land near stream flow and lakes, which were used as a water source, were designated as Riparian Buffer Zones in September 2003. For the Nakdong River watershed, three changes have been applied, making the designated area 339.9 km2. For the Geum River watershed, three changes have been applied, making the designated area 373.2 km2. For Yeongsan River watershed, four changes have been applied, making the designated area 295.6 km2. However, the following areas were excluded from the Riparian Buffer Zones: Water source protection areas, development restriction areas, and military facility protection areas, which were already subject to other regulations; sewage disposal areas, anticipated sewage disposal areas, and city areas and settlement areas designated by the Utilization Management of the Land Act that had an existing environmental infrastructure; and natural villages above level 5 for Nakdong River and above level 10 for Geum River and Yeongsan River. For areas designated as Riparian Buffer Zones, new construction of pollution sources such as restaurants, accommodation, spas, apartment housing, factories and warehouses are prohibited. After three years from an area's designation as a Riparian Buffer Zone, the existing pollution sources must discharge sewage only after it has been processed to BOD and SS levels below 10ppm. Toxic pollutants effluent standard To maintain public water quality at a level that is safe for human and animal health and for the growth of plants, pollution materials subject to management are designated under the Act on Water Quality and Ecosystem Conservation. Currently, 40 kinds of organic materials, including copper, lead, nickel, and cyanogens, are