The efficient operation of sewerage services is impacted by various factors such as geographical and topographical conditions, diversity of vertical and horizontal organizational structure, ownership types, and level of public-private partnership. The Ministry of Land, Infrastructure, Transport and Tourism, as the primary regulator of the sewerage industry in Japan, has conducted policy reforms to address issues facing the country in the 21st century: population decline, aging population, potentially high investment needs due to the aging facilities and frequent natural disasters, and fiscal pressures given the country's high debt to gross domestic product ratio. The ministry has set out several policy directions, with the most important being wide-area consolidation (WAC). Given the fragmented nature of Japan's municipally controlled sewerage system with different entities serving different customer types, the optimal consolidation strategy might differ both within and between Japan's 47 prefectures. We therefore conducted a case study of Hyogo Prefecture, which has identified several subprefecture regions within which to pursue WAC. Our aim was to gain a better understanding of how the complex characteristics and fragmentation impact not only current sewerage entity performance, but also the required approach to achieve the benefits from WAC. We argue that WAC policy objectives would be best achieved by establishing consolidated regional public sewer authorities, which should adopt one of the following consolidation strategies, depending on their own characteristics: consolidation to improve operational performance without physical integration; consolidation around a non-urban river basin system to improve treatment and collection efficiency; consolidation around a regional champion city to support small municipalities; consolidation around an urban river basin system of all operations and infrastructure; and urban consolidation of operations, collection, and treatment infrastructure.
wide area consolidation case study Japanese sewerage industry