Water is an indispensable resource for the SUBARU Group’s business activities. The risk of droughts, floods, and other disasters is increasing, however, due to climate change, while global population growth and economic development are increasing demand for water and raising the risk of water shortages and pollution.
To help alleviate these risks, the SUBARU Group is committed to the proper management of water consumption, as well as to minimizing the environmental impact of its discharged water. We are also actively engaging in activities to conserve forests that have a water storage function.
The Production & Environment Subcommittee manages the SUBARU Group’s water usage at each site, and both the total amount and amount used per unit of sales are maintained at a constant level.
The share of each water source in the total freshwater consumption at the SUBARU Group is as follows: industrial water 67%, tap water 27%, and groundwater 6%. As we are well aware of the risks involved in using the valuable resource of fresh water, we carefully monitor water consumption by conducting water risk assessments at major locations. Although the current assessment results show that the water risk is not high, we will continue to regularly assess our water risk levels and work to reduce water consumption in order to ensure a continuous water supply.
Water Risk Assessment
The SUBARU Group uses a third-party expert to implement water risk assessments* to ensure the sustainable use of water. These assessments estimated, among other things, the water supply and demand risk in the river basins in which the production bases are located, the probability of water-related disasters occurring, and the impact on public health and ecosystems on a five-point scale. Risk assessments utilized the most severe RCP8.5 climate change scenario adopted by the IPCC. These assessments showed that water risk at the Gunma Plant, Utsunomiya Plant, and Subaru of Indiana Automotive, Inc. is generally evaluated as moderate or lower.
Gunma Plant and Subaru of Indiana Automotive, Inc.
According to an assessment in FYE March 2017, the water supply and demand risk at the Gunma Plant and Subaru of Indiana Automotive, Inc., both of which are automobile manufacturing bases, is moderate. It is expected that the current risk level will be maintained for the medium to long term, even when the impact of climate change is taken into account. No biodiversity conservation areas are identified at the lower reaches of the rivers. The vulnerability to water pollution is low.
According to an assessment in FYE March 2018, the water supply and demand risk at the Utsunomiya Plant, which is our base for aerospace manufacturing, is moderate. This risk level is expected to drop in the future as an increase in the river flow rate and decrease in water demand are likely to take place. The plant is not located in an area at high risk of flood inundation or landslides. No biodiversity conservation areas or habitats for rare aquatic life are identified in the areas within 10 km downstream from the site. Going forward, we will continue to accurately monitor our water risk based on the assessments, ensure optimum water consumption in relation to local water demand, and help conserve the environment along the river.
Response to Water Risks:
Achievements and Initiatives
The total amount used is monitored and compiled for each location, and reported and verified at biannual meetings. Necessary measures are then taken as appropriate.
FYE March 2023 Water Consumption by Source (Thousands of m3)
|Region||Tap Water||Industrial Water||Groundwater||Source of Water Intake|
|Japan||317||2,857||252||Tone River, Watarase River|
|North America||852||0||0||Groundwater from the Teays Valley aquifer|
The Utsunomiya Plant has introduced a surface treatment facility equipped with an ion-exchange water recycling system that converts wastewater into pure water. In FYE March 2023, 23,389 m3 (29.7%) of the total of 78,781 m3 of water used in the surface treatment facility was recycled and utilized at the plant as washing water for the surface treatment facility.
Representative Surface Treatment Wastewater Processing and Recycling
In the Gunma region, wastewater from our plants is treated, water quality is checked in an oil-water separation tank, and it is discharged into rivers, where it eventually merges into the Tone River. Appropriate wastewater treatment is provided to ensure the water from the Tone River is safe during use for agricultural and domestic purposes in the downstream areas.
In the Utsunomiya area, after treating wastewater from surface treatment processes we discharge it into the sewer system, and discharge rainwater and cooling water into the river after checking its quality in the final water quality monitoring tank. In addition, we dispose of wastewater from the painting process in the Handa area as industrial waste, and treat domestic wastewater in septic tanks prior to discharging it into Kinuura Port and the Agui River.