Water is an essential resource in the manufacture of semiconductors.
Each wafer used to make our products goes through a series of cleaning steps, which are dependent on ultrapure water to ensure manufacturing process quality. As semiconductor technologies have become more complex, demand for water has grown. Therefore, reducing the water we use — and properly treating the water we do use — are among Micron’s top environmental priorities.
Micron proactively manages water consumption by identifying opportunities to increase water efficiency and reduce raw water demand. Our manufacturing sites generate ultrapure water from a combination of recycled water from our operations and local, untreated water resources. Wastewater from our operations that is not recycled or otherwise reused on site is treated to local standards and discharged.
Our total water withdrawal in CY18 was 48,311,910 cubic meters (m3) for our front-end and back-end manufacturing sites. This figure is up from our CY17 usage and reflects an increase in manufacturing capacity. While this water consumption figure is large, our global water recycling initiatives at our manufacturing sites achieved an approximate 50% recycling rate on average in that same time period.
A key opportunity for us to increase water recycling is through capacity expansion projects. Increasingly, we are incorporating water-saving measures at the design stage of new buildings and industrial processes at the same time as we invest resources to improve water use efficiency at existing factories.
Sustainable management of our water footprint begins with understanding where we obtain water. Globally, the primary source for water at our manufacturing locations is municipal supply, underscoring the importance of partnerships with local water authorities. We consider these relationships within their local context, seeking to understand the implications of different geographies, climates, watersheds and infrastructure. We then apply these assessments to determine the best approach to water management at each site.
In 2018, we conducted a water risk assessment using the World Resources Institute (WRI) Aqueduct tool. Through this assessment, we learned that 35% of Micron’s total water withdrawals are sourced from water-stressed areas, primarily our manufacturing locations in Singapore and China. Taiwan and Japan are additional water-stressed areas where we have significant manufacturing capacity. We take a blended approach to water management in these parts of the world. In addition to water reclamation systems at our wafer fab facilities, we have installed rainwater capture infrastructure at our expanded North Coast fabrication site in Singapore, and we source 98% of our water from reclaimed and/or desalination facilities.
In Boise, Idaho, we are mindful of our potential impact on the local aquifer that supplies the majority of our water in that location. We were early investors in technology that allows us to replenish the aquifer and mitigate withdrawal impacts.
While our approach to water supply and consumption mitigation reflects a local, adaptive approach, our commitment to ensuring that industrial wastewater discharges meet all environmental legal requirements is universal. Each Micron site has invested in significant water treatment infrastructure to ensure that the quality of any wastewater leaving the site meets or exceeds applicable water quality standards. The sites also employ staff responsible for the ongoing operation and routine maintenance of wastewater systems to ensure proper performance over time. Wastewater treatment methods may vary by site but include membrane filtration, ion-resin adsorption, precipitation, bio-oxidation and neutralization. We routinely sample wastewater discharges for conformance to environmental standards. In CY18, we discharged 37,968,559 m3 of treated wastewater, with 85% of that discharge sent to publicly operated treatment works.
We exceeded 70% reclamation rates of water at several Asia manufacturing sites and continue to invest in reclamation infrastructure across the globe.
At our Boise site, we help maintain aquifer health via regular replenishment.
In Singapore, we derive 96% of our water from rain capture, on-site recycling and NEWater. NEWater is a centralized treatment of used water that is repurposed for nonpotable use, which helps reduce the demand on reservoirs for potable water.