This paper explores sanitary engineering through the sewage system in Gyeonseong in Japanese colonial era. Once being carried out to build a new district in Hanseoung in Korean Empire, after Japanese colonial power took over the country, the project of constructing sewage system was reorganized according to its planning. The purpose of the project, as proclaimed by Japanese colonizers, was to build Gyeongseong as a sanitary city. Nevertheless, the ambition of the project was never fully realized.
There was a fundamental limitation within the sewage system that the Japanese colonial government sought to construct. The colonial sewage system was unable to collect all night soil in Gyeongseong; thus, the exceeded amount of excrement had to be disposed of through an open sewer in Cheonggyecheon. By exploring the sewage system this paper asserts that the sanitary engineering under Japanese colonial power was constructed of depleted expert training system, substantial dependence on metropole, uneven construction for different district, limited sewerage material industry, and faulty construction which includes, but not limited to, inadequate dredging, poorly established bridges and levees. The Gyungseong sewage project, which was practiced based on Japanese sanitary engineering, failed to achieve the goals of sanitary engineering.