In the social and economical surroundings of water supply and drainage nowadays near the 21st century, there are great changes such as technical innovation, progress in the information industry, internationalization, and the increase of the aged. There has been a growing tendency for the sense of value and life feeling of beneficiaries of water supply and drainage to pursue not only conventional economical efficiency but also mental life comforts such as ease, charm, and friendliness. This paper views water treatment system technology to enrich public living environment, including disaster prevention.

As industrial activities advanced and lifestyles changed, the water environment has been polluted. The Ministry of Health and Welfare and the Environment Agency have proposed the improvement and tightened control of the water quality standard for city water and water resources. This paper outlines these water quality standards and regulations and introduces biosensors and water quality meters using a new method for monitoring water quality from resources to feeder ends and for measuring and control systems in water and sewage plants.

There have been increasing demands for water such as improvement in city water quality, preservation of river water quality, and effective use of water resources. Various water and sewage treatments have been studied and developed. This paper gives an outline and technical trend of advanced water treatment using ozone and activated carbon combined to make city water safer and tastier as well as an outline of membrane filtration expected as a new water purification system. Concerning sewerage, it introduces the intermittently aerated 2-tank activated sludge process that effectively removes nitrogen and phosphorus and ozone treatment mainly intended for recycling, citing examples.

It is long since saving resources and energy was cried for against the oil crisis. Nowadays, global environmental disruption due to fossil fuel burning is at issue and in view of harmony with the environment, saving resources and energy using clean energy is advocated. This has posed problems in the energy environment of water treatment equipment. This paper introduces Fuji Electric's tackling (1) small hydroelectric and solar generation to effectively use unused clean energy, (2) harmonics suppression devices to harmonize the equipment with power supply, (3) intelligent electrical equipment to use man power effectively.

The Ministry of Ports and Telecommunications's policy for advanced information networks, as represented by the teletopia plan, is rapidly being developed. At the same time, progress is being made toward the improvement of waterworks to supply safer, better tasting water and also toward the goal of expanding sewerage facilities to reach 70% of households by the year 2000. This paper describes the needs that water supply and drainage systems have for multimedia communication, for which applications are just beginning. Systems suitable to meet those needs, such as ATM communication systems, multimedia LANs, and multimedia multiplex communication systems are also discussed.

To realize and develop a high-level infrastructure, the maintenance management of water service undertakings plays a more important part. This paper describes advanced technology for maintenance management toward the 21st century, including an example. Particularly described are advanced information processing and unmanned plant technologies, and a management system that integrates maintenance management information sent from more than one department of the undertaking.

The Hanshin Earthquake caused unprecedented, popular precautions against an earthquake. Fuji Electric always investigated earthquake-proof design and standards for equipment, system backup against disasters, and methods of minimizing disaster influences. This paper describes the concept of earthquake-proof design for equipment, installation, and systems, as well as Fuji Electric's attitude to it. In addition, a pumping system using solar generation that can be driven even when commercial power supply fails and an emergency cutoff valve using an inverter and a battery are cited as examples.

The late Hanshin Earthquake has impressed on us the great influence of information interruption in the public systems on which economical activities and social life are based. This paper examines the role of an information network system for the public systems to minimize damage and restore damaged systems rapidly when a disaster happens and in addition, describes measures to improve the reliability of information network systems and how to construct a public complex network system to reinforce linkages with other undertakings.

The Hanshin Earthquake of January 1995 has brought the various problems of the present water supply and drainage facilities against an earthquake disaster into relief. For constructing a system that solves these problems, not only hardware technology but also software technology relating to operation is necessary. This paper describes how to construct a system resistant to disasters, focusing on instrumentation and information technology.

There has been growing concern about improvement in living environment and then increasing demand for the stable operation and safety of water supply and drainage facilities. One of measures to meet the demand is the use of maintenance robots in pumping stations that will realize reduction in labor as well as stable operation. This paper introduces the maintenance robot for an unmanned sewage pumping station that was developed jointly by the Sewage Work Bureau of Tokyo Metropolis and five heavy electric machinery manufacturers in October 1992.

Water and sewage plants should do their heavy duty as a lifeline supporting present-day life. Their management systems for maintenance and supervisory control become more and more complicated and sophisticated. Fuji Electric has supplied distributed control systems for water and sewage plants, aiming at safe and accurate operation management, in which components for each function are combined by a network according to plant scales and treatment contents. This paper outlines the configuration of these systems, distributed functions and the components of a system.

The abnormal water shortage of 1994 and the Earthquake of January 1995 made us recognize again the necessity of stable water supply. Fuji Electric has supplied a large number of water control systems for the stable running of waterworks, covering raw water operation to distribution of water. The systems proved the effectiveness of our water volume distribution planning, distributing reservoir operation planning and water pressure control technologies during the abnormal water famine. This paper describes the water control technology based on our supply experiences, know-how, and constituent technologies.

In the abnormal water shortage of 1994 summer, fresh water plants so far used for industrial water supply and water supply in detached islands came to public notice as means of drinking water supply. Taking up a plant using "reverse osmosis" which is expected to be the mainstream of fresh water plants in future, this paper gives an outline and features of the plant and describes required functions for supervisory control and control functions for each equipment.