ST is committed to reducing water use and ensuring high standards of effluent and waste water treatment. We are also committed to identifying and managing water-related risks and opportunities, including impacts on local communities.
Very high levels of water purity are required to manufacture semiconductor components. ST therefore identified water conservation as a key issue in the first release of its Environment Health and Safety Decalogue in 1995. Since implementing our water strategy, which covers all stages of our operations, we have achieved yearly water draw-down reductions of 5% (cubic meters per production unit). Our overall water footprint has been reduced by more than 70% since 1994 through continuous improvement programs undertaken at all our manufacturing sites.
Pascal Roquet, Corporate Environment and Health Plan Director
“Sustainable water management is a crucial issue for both communities and businesses. ST has manufacturing sites located in sensitive areas in terms of water scarcity, quality of water or waste water pollution. Consequently we have always closely monitored our water withdrawal, use and discharge. Our objective is to constantly improve our performance."
Water management programs
At operational level, ST’s water management is based on three main activities:
• Evaluation of water use patterns
Each manufacturing site conducts regular, detailed analyses of how every drop of water is used in production processes. This enables them to identify and focus on the most water-consuming or polluting production phases.
ST’s Corporate Environment team also conducts product Life-Cycle Assessment that allows us to calculate the virtual water content of our products throughout their whole life cycle.
• “3R” approach: Reduce, Recycle, Reuse
ST sites have been initially designed to support this reduce, recycle and reuse approach. Besides, based on each site’s own assessments, specific measures are then taken to further reduce consumption and increase recycling rates, mainly through the upgrade of manufacturing equipment and processes. Procedures are regularly updated to align with best practices in terms of water loss and use of chemicals.
Recycled water is reused for less sensitive purposes such as in cooling towers, gas scrubbers and for general building cleaning.
• Treatment of discharged water
Waste water treatment plants are either located on site or developed in collaboration with local authorities. They are specifically designed to remove substances such as fluoride, which cannot easily be treated by municipal plants.
Water use management and waste water discharge management procedures detail how sites should conduct these activities, including specific requirements relating to where sites extract and withdraw water from e.g. rivers, soil and groundwater, municipal facilities. Web-based data systems enable sites and corporate functions to track and calculate sites’ water intensity.
Risks and impacts
ST recently launched a number of programs to assess water impacts and risks for ST’s business and its surrounding communities;
- Enterprise Risk Management
- Water scarcity assessment
We used the internationally recognized water stress index (WSI) to assess the potential environment impact of water use across all of ST’s locations. Seven out of twelve manufacturing sites partially or completely match specific criteria of water-stressed areas. We have been aware of our sites’ local water constraints for a number of years and we will continue to reduce our water footprint and address these constraints in site mid and long-term development plans.
- Water risk in the supply chain
In 2012, ST conducted a water risk assessment to identify the water footprint of our suppliers, as well as our manufacturing sites. Our methodology was based on the following tools: WBCSD Global Water Tool, GEMI Local Water Tool®, CERES Aqua Gauge, WWF Water Risk Filter, and WRI Aqueduct Project.
- Long-standing collaboration with surrounding communities
Our sites work closely with local stakeholders to reduce their water extraction and consumption, and to ensure a sustainable approach that takes into account the needs of a wide range of community stakeholders. This is well documented in our manufacturing sites’ EMAS Environmental Statements, available on request from each site.