Water supply systems are necessary to provide people with a stable supply of safe water. Japan's tap water enjoys a reputation around the world as being sanitary enough to drink straight from the tap. However, it has not always been this way. Even in Japan, during the late 1960s and 1970s, problems associated with water pollution became increasingly apparent.

In lakes, eutrophication caused the abnormal growth of plankton, resulting in red tides and other problems. In rivers, the source of water for cities, the water quality deteriorated due to the inflow of dirty industrial and domestic wastewater caused by population growth and industrial development associated with rapid economic growth. Under these circumstances, tap water began to have an unusual odor, such as a musty smell, which became a problem for society as a whole.

But the times have changed. Since the mid-1980s, water has needed to be of high quality as well as safe. People now expect tap water to be not only purified but to also taste great with no unusual odor or taste, and to be accessible to all. Kubota continues to work on providing a stable supply of safe and delicious water through its purification treatment technology, which has been developed through years of research and improvement.