The History of Slow Sand Filtration in Japan

Slow sand filtration (SSF) is water purifying method developed in England in 1829. It became popular in Europe and was adopted in purification plants all over the world as effective countermeasures against waterborne infectious disease including cholera, dysentery or so on. In prewar, SSF was also adopted in Japanese most purification plants since Yokohama city has introduced it as the first modern waterworks of the nation.

Slow sand filters were constructed in three prefectures of Tokyo, Kyoto, Osaka and five main port cities of Hakodate, Yokohama, Niigata, Kobe, Nagasaki where needed prevention of waterborne disease, and then spread in many parts of Japan as shown in below table.
The Akagawa Teiku Purification Plant (PP) constructed in 1888 in Hakodate city, the Sanno PP in 1904 in Okayama city, the Takao PP in 1905 in Shimonoseki city, Yamanota PP in 1906 in Sasebo city are in operation today as they were 100 years ago.

Table 1 Construction Year of Slow Sand Filter

Name of City	Year
Yokohama	1887
Hakodate	1888
Nagasaki	1889
Osaka	1893
Hiroshima	1896
Tokyo	1896
Kobe	1899
Okayama	1904
Shimonoseki	1905