The Guui Arisu Water Purification Center supplies 450,000 tons of tap water to northeastern Seoul, including Gwangjin-gu and Dongdaemun-gu.
Originally established during the Japanese colonial period, the water center expanded its facilities to include four purification plants by the mid-1980s and significantly increased its tap water supply. Although the first and second plants were decommissioned in 2002, both have been preserved as registered cultural properties.
The first plant of the Guui Water Purification Center is the oldest rapid filter basin. The high rate coagulation tank at the second plant was the most advanced facility at its time of construction, and was built with the help of the US Army Engineering Corps after the Korean War. Thanks to preservation efforts by historians and citizens, the Guui Water Purification Plant—the largest source of water in Seoul after the Ddukdo Water Filtration Center—has been maintained in its original form.