Objective: One of the major challenges for small-scale water supply systems and community water systems is the maintenance of water supply services, due to an aging and decreasing population, the aging of facilities, and other factors. This paper outlines a variety of attempts for community development in various areas in Japan, with the aim of contributing to reforms of systems for sustainability and ensuring hygiene.

Methods: The research team collected many case studies, and conducted a questionnaire survey of local governments (prefectures, cities, and special wards) throughout Japan. In the questionnaire, participants were asked questions regarding issues for ensuring the safety of the water supply and sustainable maintenance.

Results: Based on the questionnaire, cooperation among prefectures, neighboring municipalities, and residents has proven successful, and is further needed in other areas. Regarding future cooperation, 198 municipalities were interested in building partnerships with prefectures and neighboring municipalities, followed by 88 municipalities that were interested in taking an online learning course. Many others expressed a desire for on-site activities, on-site surveys, lectures, and consultation meetings.

Conclusion: There were also many attempts to conduct cooperation regarding a model for social utility creation, through the formation of a mutual aid network centered on small-scale water supplies. The sharing of common information would be effective in enhancing the sustainability of small-scale water supplies.

Objective: Facilities of water services are ageing and need to be renewed. However, renewal efforts are fraught with difficulties in the context of a declining population. These difficulties are acute, because most small-scale water supply services are located in rural areas. This paper illustrates financial systems for small-scale water services, and pays particular attention to the general account transfers, explaining the purpose for which they were introduced, how they have been developed, and efforts to attempt to cope with the problem of a declining population.

Methods: This paper collected secondary literature on the financial system, along with laws and regulations, as well as essays written by administrative officials.

Results: The main financial measures for small-scale water supply services are financial measures for construction and improvement and financial measures for reducing high-level water rates. State subsidies for construction and improvement were introduced with the aim of improving the sanitation conditions in rural villages in the 1950s. Moreover, transfers to the general account and financial measures were undertaken to reduce the financial burden on the inhabitants. These financial measures contributed to the spread of water supply systems, and as water supply services came to be regarded as a universal service, attention was drawn to the issue of water charge disparity. As a result, financial measures were established to correct such disparities. In small-scale water services, the unit cost of the water supply, especially the capital cost, is high, and, all financial measures therefore focus on the capital cost.

Conclusion: Small-scale water services are provided with generous financial measures for capital costs. The financial system for small-scale water services is characterized by the linkage between state subsidies and transfers from the general account of municipalities.

Maintaining a small-scale water supply is one of the major issues in a declining population.

In this regard, there is a particularly large impact on drinking water supply facilities that have a service population of 100 persons or less.

In this study, model districts were selected from among small water supply nationwide, in depopulated towns and villages with populations of less than 5,000.

In addition, we also conducted management simulations over the next 60 years, for independent small-scale water systems in three neighboring regions, in which various systems such as facility integration and transported water supply, have been introduced.

Based on the results, we evaluated the superiority of future water supply systems such as facility integration, the self-sustaining distributed type, transported water supply, and the non-drinking water supply, based on the average cost burden per person per month, and discussed the optimal system to be introduced in these areas.

In addition, we considered a simple and general-purpose evaluation method that could be used to study many other future optimal systems and forms of water supply for small-scale water supplies.

We considered the form that small-scale water services should take in the future.

In a society that is experiencing a declining population, focusing on small water supply systems is important. In this article, the actual situation and the perspectives of small water supply systems managed by residents or communities were illustrated, from different points of view. In small water supply systems, priority should be assigned to securing microbial safety. Accordingly, an approach for producing safe drinking water utilizing limited data was presented. After estimating the microbial risk of the source water for a water supply facility in Kyoto City, the required level of reduction by water treatment for supplying safe water was discussed.

How to supply safe water in a stable and sustainable manner, in areas without access to public water supply systems is a very important and urgent issue in many countries, including Japan. Due to time and cost constraints, as well as socio-economic feasibility, it is unrealistic to supply safe water to everyone throughout the world, using only centralized large-scale public systems. Therefore, small and decentralized water supply systems play important roles in society. This article focuses on such small water supply systems, especially those operated and maintained by communities. Case studies in Canada and Sri Lanka are introduced, based on site visits and interviews with stakeholders.

In remote areas in Canada the population density is very low, and a considerable number of community-based water supply systems are in operation. Such community-based systems are vulnerable to water quality issues, and some have been under notices such as a ‘boil water advisory ’ for more than one year. The Government of Canada is addressing small water supply systems as a part of their support services for the Canadian First Nations. Such stories are introduced, together with site visits experiences in the province of British Columbia. Meanwhile, in the North central provinces in Sri Lanka, a disease called Chronic Kidney Disease of Unknown Etiology (CKDu) is prevalent, and the drinking water of the local residents, sourcing groundwater, is suspected as a potential cause of the disease. Accordingly, the Government of Sri Lanka has been promoting the installation of community-based, small water supply systems with reverse osmosis (RO) membrane filtration units. This article introduces how such systems have been constructed, operated and maintained, along with a consideration of the challenges, based on field surveys at 32 facilities. Finally, based on the above-mentioned two case studies, concluding remarks are presented regarding the current situation and future challenges for small water supply systems.

There are many small-scale water supply systems situated throughout Japan that are not regulated by the Water Supply Act. Although these facilities are managed and operated by the residents of the communities themselves, there are concerns that the maintenance of these facilities is becoming increasingly difficult due to an aging and declining population, aging facilities, and other factors. Based on these considerations, the authors have been studying the actual status of such water supply facilities, proposing maintenance and management with cooperation from outside the community, such as the government and NPOs, as one way to ensure the sustainable maintenance and management of the water supply facilities, and examining the feasibility of support measures for such maintenance and management.

A questionnaire survey of small-scale water systems in 12 prefectures in western Japan revealed that there are many villages that use surface water without chlorine disinfection, raising concerns regarding sanitation and safety. In addition, problems such as water outages occurred quite frequently in roughly 66% of these villages, raising concerns about the fragility of the water supply in terms of stability. In addition to normal maintenance and management tasks such as inspections and cleaning of water intake facilities and filtration ponds, and transportation to and from work sites, the survey also found that emergency response tasks such as dealing with power outages, water outages, and low water pressure are also burdensome tasks.

An additional questionnaire survey was conducted to ascertain the status of cooperation with organizations outside the community and the willingness to use such support, which found that roughly 80% of these communities had never cooperated with organizations outside of the community. The same survey also asked respondents whether they would be willing to use eight imaginary support measures, if they were provided by an organization outside the village for a fee or free of charge and found that a certain number of respondents were willing to use these measures, in all cases. In addition, it was also confirmed that there was not a high level of resistance to receiving support from outside organizations.

We found that a small number of local governments are actively providing support for small-scale water systems or utilizing NPO organizations in some cases. A recently established program by the Japanese government could provide a framework for supporting the maintenance and management of small-scale waterworks in areas with rapidly declining populations. In the future, it will be necessary to survey organizations that have the potential to provide support, and to examine possible government support programs, in order to increase the feasibility of maintaining small-scale water supply facilities with the cooperation of outside organizations.

While the improvement of management efficiency through integration and wide-area collaboration is an urgent issue, in regions such as Hokkaido, where the population density is quite low, there are some situations in which it is difficult to improve management efficiency. In such areas, a drastically different approach regarding management organization should be considered. This paper introduces a new regional water supply system, based on a survey of the current situation and practical approaches, as a model for the future of water supply systems in rural areas. A survey of the actual situation in Hokkaido confirmed that the individual facilities and operational forms of the existing community-based water management system (CBWMS), as well as the support systems of municipalities, are diverse. On the other hand, the survey also revealed that many of them have achieved low-cost and easy operation, based on high-quality water sources and the ability of farmers, but have problems in water quality risk management and asset information management. Based on these CBWMS characteristics, Furano City in Hokkaido and the authors have been working with local high school students to create a support system for CBWMS. Through five years of practice, we have learned that: the information created by the high school students is sufficiently valuable for the local community; the local high school is a place to nurture the next generation of leaders in the community, and activities by high school students to learn about the community can contribute to the revitalization of the community; and, the network of local high school graduates can be utilized to build a local network for water supply restructuring. We estimated that the personnel and costs required to develop a similar support system in another location would be as follows: the initial cost is approximately 73,000 yen (if PCs are already available at the local high school), the annual cost is approximately 51,000 yen, and the manpower required for the cooperation of an outside researcher, such as the author is approximately 6 man-days/year. As described in this paper, the establishment of a support system in cooperation with local high schools, as well as a support system by municipalities in a reasonable manner will be important to support the sustainability of small-scale water supply systems in the future.

The use of quality-adjusted life year (QALY) as a measure of benefit is recommended in economic evaluation, which aims to provide evidence for the appropriate allocation of health care resources. This allows for an easier comparison of interventions' effects in different fields. A QALY value is calculated by weighting the life years (LYs) by the quality of life (QOL) score, which is determined by preference-based measure (PBM) and converted from 0 to 1. The QOL score should be obtained through domestic surveys because it reflects the value in the country's general population. In Japan, the data of the QOL scores for adults have been accumulated in recent years. However, few studies for children have been conducted due to various issues in evaluating pediatric health-related QOL (HRQOL). The PBM process for obtaining the QOL score can be divided into “measurement” and “valuation” of the health state to be evaluated. This process is implemented at once in direct methods, whereas it is carried out separately in indirect methods. Direct methods include the rating scale, the time trade-off, and the standard gamble, but children's feasibility, reliability, and validity must be thoroughly investigated. In indirect methods, which is currently the mainstream in general, multi-attribute utility instruments (MAUIs) are used, consisting of a questionnaire to measure the health state and a value set to value the measured health state. However, most MAUIs are designed for adult use and are not suitable for pediatric use because the questions are inappropriate, and the value set is intended to value adult health. In recent years, some MAUIs for pediatric use have been developed. Nevertheless, due to translations and the value set, these are not available in all countries. Additionally, there are no existing MAUIs available for children aged 3 years. Furthermore, issues concerning “measurement,” such as which domains should be assessed and how, and by whom, and issues concerning “valuation,” such as whose preferences should be reflected in developing the value set, and which perspectives should be used, remain. There have been no MAUIs for pediatric use in Japan, but the Japanese version of the EuroQol 5-dimension Youth version (EQ-5D-Y) and its value set have recently been published. It is necessary to fully understand the challenges and limitations in measuring and interpreting the QOL score in children.