ROLES AND CONTRIBUTIONS OF INDUSTRIAL WATER SUPPLY WORKS IN JAPAN

Following the previous issue of the JFS Newsletter, this month we present one more article on water.

Water is said to be the lifeblood in industry, and Japan's industry runs on a system of industrial water supply works that are unique in the world, designed to ensure a stable and reliable supply.

Industrial water supply works provide water for factories and other industrial facilities. The water purification treatment done for industry is simpler than for drinking water, keeping down the water costs of industry.

Japan's industrial water supply works were one of the major driving forces behind Japan's period of high growth economic period that began in the 1950s and have also played an important role in mitigating and prevent ground subsidence and groundwater salinization problems.

As of 1998, 38.5 percent of Japan's industrial water came from industrial water supply works, followed by groundwater (27.5 percent), rivers (25.7 percent) and tap water (7.2 percent). At present, there are 243 industrial water supply works operated by 137 agencies (2 private), supplying 32,592,000 cubic meters of water per day nationwide.

Most industrial water supply works in Japan are operated by local governmens at the prefectural, city and town level. Water is withdrawn from lakes, dams and rivers and treated by simplified methods, then sent to industrial areas by pipes. This water quality is the same as drinking water, except that it has not been filtered and sterilized.

In 1937, Kawasaki City started supplying water to industrial areas using industrial water supply works in order to mitigate problems of a falling water table. Since then, many local governments started to construct industrial water supply works. The Industrial Water Law was enacted and government subsidy framework for industrial water supply works was established in 1956. In 1958, the Industrial Water Supply Works Law was formulated, promoting infrastructure for industry.

Starting around 1950, industries began to develop rapidly and many factories were built. The excessive consumption of groundwater by industry resulted in ground subsidence in many places in Japan. As countermeasures, groundwater pumping for industrial use was restricted and industrial water supply works were promoted as alternative water sources.

For example, the Tokyo metropolitan area suffered from ground subsidence of 10 to 13 cm per year during the mid 1960s. After construction of the industrial water supply works, water supply from the works increased and ground water pumping for industry decreased, reaching virtually zero in the 1970s. As a result, ground subsidence stopped. In other areas too, ground subsidence, once considered a major problem in Japan, was mitigated or eliminated during the 1970s.

In recent years, due to flattened demand for industrial water, industrial water supply works deliver water not only to factories and industrial facilities but also to other places for other uses, such as in cooling towers and flush toilets of buildings and housing complexes; watering of parks, green areas and golf courses; and washing of taxies and garbage trucks.

Demand for industrial water supply has not increased for many years, because the recovery ratio of industrial water (amount of water per unit of water consumed) has risen significantly, for example from 36 percent in 1965 to 78 percent in 1998, meaning that there has been no need to increase the supply of fresh water to industry.

Meanwhile, industrial output in Japan quintupled between 1965 to 2000. Fresh water intake for industry during the same period, however, did not increase. This means that fresh water consumption per unit of industrial output decreased to one fifth. In the area of industrial water, Japan's rapid economic growth was achieved by "getting more from less."

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