Many global environmental problems are occurring and they have deep relation to water and sewage treatment systems. Social environments around water and sewage waterworks have also changed greatly
On the other hand, system control technology has made remarkable progress and has pushed many researches and developments in connection with water treatment.
This paper describes the governmental policy against environmental changes and the trend and view of water treatment system technology toward the 21st century.

Recent changes in natural environments have badly affected water resources that are deeply related to our social activities. Particularly the sources of water supply such as lakes, rivers and underground water, have been worsened and advanced treatment functions and technologies are required to reap safe and tasty drinking water. As high-level waterworks expected towards the 21st century, this paper describes measures for water control systems to cope with the changes of water resources.

The improvement of sewage systems these days aims not only at service area extension and overflow prevention but also at high-grade sewage treatment and sludge utilization as resources in connection with environmental problems.
This paper describes the trend of recent Fuji Electric's technologies in this field, such as high-grade sewage treatment, system technology for clean energy and sewage sludge energy, environmental measuring technology, and supervisory control technology.

The pollution of water, air, greens, and soil has been discussed as global environmental problems from every point of view. To grasp water pollution in water environment accurately, water quality measuring technology has become more important than ever.
Fuji Electric has developed water treatment system technology for many years and has positively taken up water quality sensors because they are essential in the optimum control of processes. This paper introduces 6 types of conventional but improved water quality meters and 9 types to meet new social needs including an ozone analyzer.

Water and sewage treatment plants have been an essential part of the infrastructure of modern social life, and integrated control systems to execute their planning, maintenance management and operation are more and more important.
Fuji Electric supplies integrated control systems for water and sewage treatment plants, corresponding to the scale and purpose of work to be controlled so that complicated and advanced works can be managed by mean of simpler, easier system. This, paper outlines the system configuration and functions.

The renewal of electrical equipment in water and sewage works is planned not only to improve reliability and maintainability but also to solve existing problems in operation control and maintenance control into the future business plan from a viewpoint of whole system.
The planning of system renewal aims at (1) improving operation control functions, (2) realizing reliable systems, and (3) automation of control. The result of renewal work depends on defining the aim of system renewal at a planning or designing stage, that is, the function and performance of a new system.

Control rooms for water treatment plants had a tendency to give priority to the reliability, safety and durability of machines and systems over the working environment of human operators. Recently, however, the improvement of human working environment including machine operability has been regarded as more important to prevent human error as well.
Fuji Electric holds up a concept "Work as Live" toward comfortable environment and proposes new control rooms as a system of operators and machines.

The automation and systematization of plant operation management are increasing demands by water and sewage plants. An intelligent management system has been installed to solve these problems. The system is based on the know-how of human senses and operator's knowledge experienced for many years. This paper introduces Fuji Electric's achievements of AI, Fuzzy, Newro and image processing.

The days of mere construction is over and modern times pursue abundance. Electronic components have remarkably developed, so that electrical equipment has been made small and intelligent. From among Electrical control(E), Instrumentation (I), and Computer (C) composing electrical and instrumentation technology for water and sewage works, this paper outlines the following intelligent E items and their effects; (1) FALONET(Fuji Aqua Local NET work) system for electronic, multifunctional control centers and HV/LV switchboards, (2) Variable-speed drives and measures against harmonics, (3) Up-to-date technology for receiving power.

The Ministry of Health and Welfare issued "Long-term plan for water supply improvement toward 21st century (Fresh water plan)" aiming at high-grade water supply. Recently, water supply systems have been advanced and then malfunction management has become still more essential to water distribution control systems. The controls under normal conditions have been discussed with by many papers and used effectively in actual distribution plants. However, this paper describes systems to realize stable water supply focusing on water distribution control system under abnormal conditions.

Introducing advanced treatment was started by waterworks as a part of "Fresh water plan" toward the 21st century, in Japan, and by sewage works for recycling water resources.
This paper outlines problems and steps when planning an advanced treatment system in use of ozone treatment from among advanced treatment processes, such as technology to optimize reaction tank design by evaluating characteristics with simulation, measures against harmonics from the power supply of large-capacity ozone generators, and the points of supervisory control systems.

The point of water and sewage works changed from quantity to quality, and maintenance management has become more important. On the other hand, problems of aging, labor shortage, working conditions of ill repute are now faced, and it is urgent problems to improve working conditions and to strengthen maintenance management capacity.
This paper introduces a maintenance management support system to solve these problems by robots to improve working conditions and diagnosis technology including recent AI expert systems.

The ratio of small and medium towns using the sewage system is still low in Japan and many small-scale sewage facilities are under construction.
Fuji Electric has made plans for electrical system, instrument, and monitoring equipment based on the characteristics of small-scale sewage systems. Efficient systems can be structured by centralized supervision, unmanned systems, and operation support systems. This paper describes the systems and also prospects toward the 21st century.

The management center system supplied to Kanagawa Prefectural Water Supply Corporation is a large-scale integrated water distribution management system containing a super-minicomputer (A-500) as the core. It aimed mainly at the total water distribution control and realized integrated management including maintenance management, office management, and a part of business management. Total design with human engineering was used for the central control room including interior finish and illumination. It is expected to be the prototype of an integrated water distribution management system.

This paper introduces a supervisory control system supplied to the new medium-scale water treatment plant at Atushiokanomura, Fukushima Pref. the latest centralized-supervision, distributed control system FAINS-1000 is used. Two CRTs combined with a mini graphic desk and a map panel as man-machine interface improve operability and save labor. Controllers distributed at each equipment realize local completion of control and diversification of risks. A high-speed, high-reliability optical detaway is used for transmission between systems. The service reservoirs are remotely monitored and controlled with the telemeter.

Shibaura Treatment Center of Sewerage Bureau, Tokyo Metropolis, is a confluence type sewage works with a treatment capacity of 1.13 million m³ /day at present. As the old supervisory control systems were constructed from 1972, when a series was added in 1989, the integration of supervisory control systems was carried out including the renewal of the existing system. This paper describes an outline of this renewal and the features of the new system.