Farmland to sea: the contemporary policy history of night soil management in Tokyo

To manage night soil, establishing a modern sewerage system is necessary, but its completion takes a long time. If night soil is not appropriately managed, a city can immediately become paralyzed. How do governments manage night soil prior to the completion of a sewerage system in modern society? This paper describes the contemporary policy history of night soil management for the twenty-three wards of Tokyo, which is a unique and informative case. The Tokyo Metropolitan Government (TMG) attempted to maintain the traditional system of managing night soil, which was delivered to farmland as a source of agricultural fertilizer until the 1960s. Because the demand for artificial chemical fertilizers has dramatically increased across Japan since the 1960s, the TMG was forced to depend on dumping night soil into the sea to keep Tokyo clean. In 1967, the leftist and liberalist Ryokichi Minobe was elected governor on a promise to promote welfare and environmental policy. However, he saw no choice but to dispose of night soil into the sea until the completion of a modern sewerage system. The transition in the management of night soil, from delivering it to farmland to disposing of it in the sea, was a considerable change, but the decision was made within the scope of routine administrative work. This paper presents a detailed study of the management of a social nuisance in the field of policy history.