Sustainability

Efficient Use of Water Resources

In line with our Basic Environmental Protection Policy and Environmental Vision 2050, at Fuji Electric we seek to contribute to the realization of a recycling-oriented society. To this end, we are working to ensure that we use water resources efficiently and comply with all applicable wastewater standards.

Efficient Use of Water Resources

The issue of water resource depletion has become global in scale. As such, in addition to complying with wastewater standards, at Fuji Electric we have set ourselves targets for reducing water intake per unit sales, as a way of promoting the effective use of water resources. In fiscal 2023, company-wide water intake rose 4.8% year-on-year, due to an increase in the production of semiconductors at our Malaysia Factory. However, company-wide water intake per unit sales stood at 890 m3 per 100 million yen, a year-on-year improvement of 3.9%.

In order to ensure water resources are effectively used, we have also started recycling water. Our water recycling rate for fiscal 2023 stood at 21.0%, almost identical to the previous year. In order to further improve our water recycling rate, we have installed additional recycled water production facilities at Matsumoto Factory, and these commenced operations in December 2023.

Water Risk Assessments

Fuji Electric carries out assessments to confirm whether there is any risk of water shortages at manufacturing sites in Japan or overseas. These assessments have indicated that the Shenzen Factory in China is the only site with a high risk of water shortage.

The Shenzhen Factory is our only facility in the region deemed to have a water risk. Reliable supply of water is essential for the production of photoconductors. Since water supply is restricted during the dry season, we are taking two major risk countermeasures.

First, we are installing water tanks. This enables us to avoid any impact even if water supply is temporarily suspended. Second, we are introducing equipment to recycle wastewater. Our current recycling rate is 80%, which is higher than the 70% target decided by Shenzhen City. This has helped us build a good relationships with the local government and establish a production system that allows for the stable use of water.

Water purchased and used at our sole facility with water risk

Status of water intake management

At Fuji Electric, the majority of our production facilities are located in industrial parks, which are supplied with both industrial water and drinkable tap water; some of our facilities use groundwater, too. We provide annual reports on groundwater intake volumes to the relevant authorities, and make efforts to ensure we use local water resources in an appropriate manner. We use groundwater at 15 of our 19 facilities in Japan, and it accounts for 52.3% of our total water intake volume. In the past, intake of groundwater has resulted in land subsidence in Japan; today, however, the government has established standards to ensure that water intake volumes are managed appropriately. Accordingly, social issues caused by water intake are almost non-existent.

Only one of our 14 overseas facilities use groundwater, and it accounts for just 0.04% of our total overseas water intake volume. At Matsumoto, Yamanashi, Tsugaru, and Malaysia Factories, which use particularly large volumes of water in their front-end semiconductor processes, and at Shenzhen Factory we promote water recycling as a way to control and manage water intake volumes.

At other sites, too, we act swiftly in cases where ISO 14001 environmental impact assessments identify significant impacts due to water consumption. In addition to conserving water in our everyday activities, we also work to ensure the early detection and repair of water leaks, invest in water recycling systems, and install above-ground piping for visualization purposes.

Status of wastewater management

We strictly control wastewater at factories that use chemical substances. We have also established our own standards for wastewater management, which are stricter than those mandated legally. If an abnormality is detected in the wastewater treatment system, we have resident repair personnel in place to respond immediately. If we detect inadequate pH adjustment or similar problem, our drainage outlets are automatically shut down to prevent wastewater that does not meet official standards from being discharged externally. This substandard wastewater is kept in drainage reservoirs until remediation is completed.

By strictly managing wastewater in these ways, we strive to minimize the impact of our activities on the ecosystem.

Efforts to effectively utilize water at our production sites

Matsumoto Factory uses large amounts of water in its front-end semiconductor processes, so it is making efforts to recycle water as a way of reducing its environmental load. Thanks to new recycled water production facilities that commenced operation in December 2023, in fiscal 2023 the Factory increased its use of recycled water by 6.5% year on year, and also improved its recycling rate by 0.3%; hopes are high that the year-round use of these water recycling facilities will contribute to even greater improvements at the Factory. Going forward, we will continue to strengthen our water recycling and our water intake reduction activities.

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Efficient use of water resources at Matsumoto factory

Our Matsumoto Factory, where we make semiconductor wafers, uses large amounts of pure water in the wafer fabrication process and a lot of water for cooling production equipment. Therefore, it is important that we reduce water usage and utilize our water resources effectively.

New Integrated Water Management

Pure-water recycling initiatives:

Wastewater from the manufacturing process is sorted and relatively high-quality portions are recycled as raw water for pure water production.
To enhance recovery of wastewater from the washing process, we have successfully made bioactivated carbon filters with Microbacteriaceae, known for its treatment capability of organic substances, and thus improved the recovery rate. For wastewater containing fluorine, which is harmful to the environment, we have introduced a dedicated wastewater recovery system that uses a reverse osmosis membrane to concentrate wastewater and reduce its volume. Moreover, clean water that has passed through the membrane is reused as raw water for making pure water.

Reducing chemical use at hydrofluoric acid treatment facilities:

The water purification process requires regular regeneration of ion exchange resins, which produces a mixture of acidic and alkaline wastewater. At Fuji Electric, we previously neutralized this wastewater and, after terminal treatment, discharged it into the public sewage system. Wishing to reduce our use of chemicals, we devised and introduced a new wastewater recycling system that separates high-concentration alkaline solution from wastewater, and reuses this alkaline solution to make the necessary adjustments to pH levels for our hydrofluoric acid treatment equipment. This has enabled us to reduce the amount of chemicals used, as well as overall costs.

Building a new wastewater recycling system

In addition to our existing Integrated Water Management (IWM) wastewater recycling system, in fiscal 2023 we commenced operations of a new wastewater recycling system. This new system is capable of recycling twice the volume of wastewater of the existing system and, thanks to various improvements, the treated water is of a high enough quality that it can be used for air-conditioning. This has enabled us to increase production without having to dig new water intake wells. Going forward, we will continue to consider ways of reducing our use of water resources.

Improved wastewater recovery system using integrated wastewater management (IWM):

For the factory’s final treatment process, we installed an integrated wastewater management (IWM) system. Under the system, wastewater that previously was discharged into the public sewage system is reclaimed (through filtration treatment and the like) and reused as water for the plant’s cooling towers and toilets (approximately 1,000 tons/day).Recently, the recovery rate has improved due to improvements in filtration membrane maintenance methods, etc. In fiscal 2023, we aim to increase drainage recovery by 50% compared to previous years, as our new drainage recovery system starts operating in conjunction with the existing drainage recovery system.