Water Supply Service Act (Act No.177 of 1957).

This Water Supply Act aims to ensure the safe, sufficient, and affordable supply of clean water in Japan by regulating the construction, management, and strengthening of water supply systems. It establishes responsibilities for national and local governments, water suppliers, and citizens to maintain water quality, manage resources efficiently, and promote public health. The Act defines key terms, sets water quality and facility standards, and outlines the authorization process for water supply services, including requirements for business plans, technical supervision, and regular inspections.
The Minister of Land, Infrastructure, Transport and Tourism shall regulate the basic policy for strengthening the infrastructure of water supply (art.5.2). A person who intends to manage water supply services must be granted authorization of the Minister of Land, Infrastructure, Transport and Tourism (art.6). Water supply utilities shall conduct periodic and temporary water quality inspections pursuant to the provisions of the Ordinance of the Ministry of the Environment (art.20). A water supplier shall implement regular and extraordinary water quality testings in accordance with the provisions in Ministerial Order of the Ministry of the Environment (art.22).
The Act also covers the management of privately owned and building water supply systems, emergency measures during disasters, and penalties for violations. It emphasizes collaboration among stakeholders, technical and financial support from the government, and transparency through public information. In addition, the Act includes provisions for supervision, reporting, and administrative review, ensuring that water supply operations remain reliable, safe, and responsive to public needs.