Effective Use of Water Resources

The SUMCO Group recognizes that water is an important resource playing a vital role in manufacturing silicon wafers. We have set environmental objectives related to reducing water used by our business, and we are working to use water resources effectively at all of our manufacturing bases.
The SUMCO Group’s water recycling rate hovers at around 39% and was 36.6% in 2022.

At our plants in Japan and overseas, 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.

Water Recycle Flow (SUMCO Group)

Cooperation with Stakeholders

• Disclosures through CDP (Water Security)

The SUMCO Group disseminates information regarding its ESG efforts to a wide range of stakeholders.
Starting 2021, we respond to the water security questionnaire conducted by the CDP, which publishes information on companies’ environmental initiatives according to common measures.

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 2022 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
	Kyushu Factory (Nagasaki)	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	4
	FORMOSA SUMCO TECHNOLOGY CORPORATION	2

• *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.

• To ESG-oriented Investors