The water supply directly affects people's living and lives. If water is not safe to drink, people's health and even their lives would be seriously threatened. Therefore, water must be absolutely safe. Because of this, the ministry has traditionally striven to secure the supply of safe, high-quality water. Despite such efforts, however, in the last few years new health problems, including water-origin infectious diseases caused by pathogenic protozoa such as cryptosporidiums have been caused. In the meantime, the WHO revised its water quality standards. Such circumstances have created a strong need for measures to preserve the quality of source water for public water supplies, for more-sophisticated purification methods, and for even stronger water-quality management relating to the water supply.
(1) Preserving the high quality of source water for public water supplies
The increased contamination of source water for public water supplies in recent years has made it necessary not only for water suppliers to strive for upgrading their purification method but also for other related parties to take fundamental measures to preserve the quality of source water itself in order to supply people with safe, high-quality water.
Because of this, pursuant to the "Law to Promote the Implementation of Programs to Preserve the Quality of Source Water for the Public Water Supply", water suppliers that through their own efforts might not be able to meet the quality standards for publicly supplied water have requested that the relevant prefectural government formulate a prefectural program and that the river administrator prepare a river-administration program. Under these programs, systematic measures to preserve the quality of source water for public water supplies are being promoted, through the development of sewerage systems and through programs to develop river environments. By January 1999, requests from water suppliers to establish a program in compliance with the law have been made concerning 11 places. Of the 11 places, prefectural programs have been established for seven places and a river-administration program for one place.
(2) Controlling the quality of water supplies
It is important to appropriately and definitively implement water-quality controls, including quality tests of public water supplies, in order to constantly supply people with safe water. Accordingly efforts have been made to strengthen and expand water-quality control systems in accordance with the water-quality-control program of each prefecture. In the meantime, the Expert Committee on Water Quality Management, Public Water Supply Group of the Living Environment Council has revised standards concerning the quality of public water supplies in light of developments at the WHO. The committee prepared a report to request the addition of supervised items, etc. in December 1998.
(3) Measure against cryptosporidiums
As for measures against cryptosporidiums, efforts have been made for thorough management of turbidity under the "Policies concerning Temporary Measures against Cryptosporidiums Contained in Tap Water" (Policies concerning Temporary Measures). The "Guidelines for the Execution of Health-Risk Management of Drinking Water" have also been set, according to which information is collected when an accident threatening the lives of people and safety of health is caused by drinking water. Measures for health management such as those for the prevention of occurrence and expansion of health damages are taken also in accordance with the guidelines.
The Policies concerning Temporary Measures were revised in June 1998 to upgrade the test methods, etc., based upon new knowledge including research and study results obtained at the "Discussion Meeting on Measures against Pathogenic Protozoa Including Cryptosporidiums in Tap Water".
2. Aiming to Supply Higher-Quality Water
(1) Bringing public water to non-supplied areas
Food poisoning cases caused by Entero-hemorrhagic Escherichia coli O157 and contamination of underground water have surfaced as new problems in the last few years. Tap water, however, has been chlorinated and is managed according to the water quality standards, which enables the supply of clean water. In order to secure an improved, hygienic environment for all the people, even stronger efforts are needed to provide public water to areas that do not yet have it. As of the end of fiscal 1997, the number of people living in areas without public water supply, which are mostly farming and fishing villages, reached around 4.91 million, and the expansion of the water supply to such people has become an urgent need.
At the same time, many of the approximately 12,000 water suppliers in Japan are faced with problems such as requirements to strengthen the technical and financial foundations of their operations and to reconstruct, renew, or upgrade superannuated facilities. To cope with these problems, the national government is supporting efforts by municipalities to expand water supplies through financial and other support, including government subsidies for the introduction of small-scale public water-supply facilities.
(2) Promoting the development of advanced purification facilities
Further contamination of water in recent years has given rise to new problems such as the existence of trihalomethane and other oncogenic substances in tap water, and offensive smells and tastes as well. The introduction of advanced purification facilities to conduct ozonization, activated carbon treatment, and so on is being promoted in order to cope with these problems. In the meantime, since fiscal 1997 the introduction of membrane-filtration facilities has been promoted, because these can definitely eliminate pathogenic protozoa, including cryptosporidiums. Membrane-filtration facilities require only a relatively small amount of space, and they are capable of automatic operation. It is anticipated that they will be diffused as next-generation purification facilities for small-scale water-supply systems.
Moreover, for the renewal of superannuated purification facilities, the development of high-efficiency purification technology requiring only limited space is being promoted. This will allow new facilities to be constructed without suspending the operation of existing purification facilities, even if sufficient space cannot be secured pursuant to the relevant filtration plant.
(3) Expanding the direct supply of water to the upper floors of buildings
In Japan, the water pressure is low, and for buildings of three or more stories there has to be installed on the site a water-reception tank from which water is supplied to each story. Nevertheless, some water-reception tanks are not appropriately managed and could have hygiene problems. Because of this, technology to allow water to be supplied directly up to about the tenth floor of a building has been developed and the research results were notified to prefectural governments as technical data in 1997. At the same time, projects to replace old pipes with new ones that can stand higher water pressure are being promoted through government subsidies, etc.
3. Establishing Water-Supply Facilities that are Resistant to Earthquakes and Water Shortages
(1) Measures to improve earthquake-resistance
The Great Hansin/Awaji Earthquake, which occurred in 1995, badly damaged water-supply facilities, while the long time during which water supplies were cut-off seriously affected people's lives. To incorporate in water-supply administration measures the lessons learned through this experience, measures are being actively promoted to improve the earthquake resistance of water-supply facilities and to develop new technology related to this, including the introduction of water pipes having stronger earthquake-resistance and the development of trans-regional water-supply facilities. In addition, in January 1997 a report was prepared, which was titled "Policies in Formulating Plans to Improve the Earthquake-Resistance of Water-Supply Facilities (Draft)". All prefectural governments have been notified of these policies. The ministry intends in future to systematically promote the setting of targets in accordance with the characteristics of each particular water-supply facilities, the expansion and strengthening of emergency measures including emergency water supply and recovery works, and the improvement of the earthquake-resistance of facilities.
(2) Measures to prevent water shortages
Water shortages have occurred frequently in recent years. To prevent additional water shortages, the revision of our uses of water and efforts for becoming a water-saving society have been promoted. Also, in order that existing water resources can be utilized as effectively as possible, efforts have been promoted for the development of integrated water-supply facilities and the prevention of water leakage. Other efforts include the construction of dams, the development of desalinization facilities, the securing of wells as water sources during emergencies, and the installation of water service reservoirs.
4. Deregulation Concerning the Public Water Supply
(1) Deregulation concerning water-supply equipment
Under the System to Designate Constructors of Water-Supply Facilities, water suppliers have designated the constructors to install water-supply equipment. As a result of the revision of the Water Supply Law in June 1996, designation requirements for constructors of water-supply equipment were standardized and national qualifications were established for chief engineers in construction works of such facilities. The amended law was fully enforced in April 1998.
With regard to regulations concerning the use of water-supply tools, the Enforcement Ordinance of the Water-Supply Law was revised in March 1997 to clarify the structural and material standards of water-supply equipment and to standardize its performance. Information on the conformity of each product with the standards is provided through the Internet. Functions to accept claims, information, etc. were added in July 1998. (http://www.mizudb.or.jp/KYU_Menu.html)
(2) Deregulation concerning water quality test
Furthermore, under the Plan for Promoting Deregulation that was decided upon by the cabinet in March 1997, it was agreed that discussions would be made about standards for the designation of organizations to conduct water quality tests on publicly supplied water. Accordingly, discussions were made at the Living Environment Council, which concluded that the standards should be revised to abandon the provision limiting the organizations to conduct water quality tests to nonprofit foundations. In response, a notification allowing private test organizations to conduct water quality tests after obtaining designation was proclaimed in November 1998.
Figure 6-6-1. Establishing a Safe, Reliable Water-Supply System that is Earthquake-Resistant and
that Prevents Water Shortages