Effective Use of Water Resources

The SUMCO Group recognizes water resources play a vital role in manufacturing silicon wafers. We have set environmental objectives related to reducing water used by our businesses, and we are working to use water resources effectively at all of our manufacturing bases. In Japan, we utilize the reject water generated in the water purification process as cooling water for utility facilities and dilution water for wastewater treatment chemicals. We are also working to conserve as much water as possible for recycling, such as collecting the rinse water used to clean silicon wafers.
Our water recycling rate hovers at around 40% and was 39.4% in 2018.

Amount of Water Recycled and Recycling Rate
(SUMCO Group [Japan])


Amount of Water Supplied and Discharged
(SUMCO Group [Japan])


Amount of Water Consumption by Water Source (SUMCO Group [Japan])


Water-stressed Areas

The SUMCO Group investigates water stress using the AQUEDUCT tools provided by the WRI*1. The following shows the results of the 2019 investigation.

Operating Base Water stress*2
Includes SUMCO Group companies in Japan Kyushu Factory (Nagahama, Imari) 2
Kyushu Factory (Kubara, Imari) 2
Kyushu Factory (Saga) 2
Yonezawa Plant 1
Chitose Plant 1
JSQ Division 1
SUMCO TECHXIV Corp. Nagasaki Plant 2
SUMCO TECHXIV Corp. Miyazaki Plant 1
SUMCO Technology Corp. Noda Plant 2
SUMCO Group Companies Overseas SUMCO Phoenix Corporation 3
PT. SUMCO Indonesia 3
  • *1WRI: The World Resources Institute. A U.S. policy center.
  • *2Water stress: Evaluated on a scale of 1-5. The higher the number, the more water-stressed the area is.