Introduction of slow sand filter facilities in Japan

Slow sand filter system is used in many water supply utilities of Japan because the mechanism is easy, the maintenance costs are low and the quality of water is high.
The amount and size of slow sand filter system decreases in Japan. But slow sand filtration system is used by 298 waterworks and about 2000 small‐scale water‐supply system in Japan.（2011 statistics on water supply, Japan Water Works Association）
Filtration flow of slow sand filter system makes up only 4 percent of all filtration flow in Japan.
Slow sand filtration system isn’t used much in large water supply utilities of Japan.

Large-scale slow sand filters which are rare in Japan, old slow sand filters which are used since it is constructed more than 100years ago and new slow sand filters which are constructed recently is reported in this page with pictures.( the guide of Japanese water purification plant 2008, SUIDO SANGYO SHINBUNSYA)

Kitayamata water purification plant in Kusatsu City, MIiyaura water purification plant in Hiroshima Prefecture, Kikukawa water purification plant in Shimonoseki City and Sodeyama water purification plant in Miyakojima City and so on have pretreatment facilities except plain sedimentation basins.
Kitayamata water purification plant has coagulation-sedimentation process, primary filtration and slow sand filter.
MIiyaura water purification plant has coagulation-sedimentation process and slow sand filter.
Sodeyama water purification plant has scrubber and slow sand filter
Sodeyama water purification plant has reduction facility of hardness and slow sand filter

１．Large-scale slow sand filters in Japan

Sakai water purification plant in the Tokyo waterworks
Location: 8-37 Sekimae1-chome, Musashino City, Tokyo
Start of water supply: 1924
Capacity of facilities: 21,520 cubic meters per day
Water resources: surface water in the Tama river


Nabeyaueno water purification plant in the Nagoya waterworks
Location: 1-33 Miyanokoshi-cho, Chikusa-ku, Nagoya City, Aichi Prefecture
Start of water supply: 1914, September
Capacity of facilities: 140,000 cubic meters per day
Water resources: surface water in the Kiso river



Soneya water purification plant in the Ueda waterworks
Location: 2250 Kosato, Ueda City, Nagano Prefecture
Start of water supply: 1923
Capacity of facilities: 57,000 cubic meters per day
Water resources: surface water in the Kan river(67%), surface water in the Chikuma river

(Photo by Toshin Journal Co.,Ltd.)

２．Old slow sand filters in Japan

Mino water purification plant in the Okayama City waterworks
Location: 1-2-1 Mino, Kita-ku, Okayama City, Okayama Prefecture
Start of water supply: 1905
Capacity of facilities: 20,450 cubic meters per day
Water resources: Asahi river
registered tangible cultural property of Japan, selected one hundred modern and exquisite water facilities of Japan




Takao water purification plant in the Shimonoseki City waterworks
Location: 8-1 Kasuga-cho, Shimonoeki City, Yamaguchi Prefecture
Start of water supply: 1906
Capacity of facilities: 13,400 cubic meters per day
Water resources: Utsui 1st reservoir and Utsui 2nd reservoir in the Ayaragigawa river system
registered tangible cultural property of Japan


３．New slow sand filters which is constructed recently
Miziro water purification plant in the Shimane Bureau of Enterprise
Location:96-2 Miziro, Kamo-cho, Unnan City, Shimane Prefecture
Start of water supply: 2011
Capacity of facilities: 35,000 cubic meters per day
Water resources: underground water in the Hii river