Water Management

Semiconductor processes have become complex as they advance from 2D structures to a 3D FinFET architecture, which in turn increases the types and quantity of the chemical materials used. Water is vital to cleaning wafers and maintaining a clean environment. TSMC has established various water recycling applications through water resource risk management, expansion of diverse water sources, and the development of pollution prevention techniques in order to maximize the efficiency water use throughout the water cycle in its facilities. In 2019, the Company took further steps to regulate the water management framework of its facilities to ensure the reasonable allocation of facility water resources in response to seasonal temperature changes.

Strategies, Targets & Achievements

Strategies
  • Risk Management of Water Resources
    Enforce climate change mitigation policies, implement water conservation and water shortage adaptation measures
  • Develop Diverse Water Sources
    Integrate internal and external company resources to develop regenerated water technology; implement water conservation and the use of regenerated water in the manufacturing process
  • Develop Preventive Measures
    Improve the efficiency of water pollution prevention and removal of water pollutants
2018
2019
2030

Five Actions of Water Resource Management

TSMC believes water resources management plays an important role in climate change and natural disaster adaptation. The Company has developed five core actions in line with our strategy to reach our water resource management goals.

Water Conservation Measures and Results

In an effort to develop more water-saving methods, TSMC's water conservation guidelines focus on four aspects: reduce water consumption by facility systems, increase wastewater recycling in facility systems, improve system water production rates, and decrease water discharge loss from the system. In 2019, 3.28 million tons of water was conserved.
TSMC's water sources include tap water, air conditioning condensate water, and rainwater. In order to comply with water supply diversity policies, TSMC has been promoting the development of water reclamation and support it with tangible actions to expand the supply and recycling of sustainable fresh water.
Note: Water supply schedule and water supply volume for 2021 and thereafter are calculated from reclaimed water consumption contracts between TSMC and government departments (Southern Taiwan Science Park Administration and Tainan City Government)
The average recycling rate of the water used in production processes reached 86.7% in 2019, the total amount of water recycled by TSMC reached 133.6 million tons and surpassing annual water saving targets by 187%.
A total of 38 distribution systems have been established based on the composition and concentration of wastewater from manufacturing processes. TSMC has built a comprehensive wastewater classification and resourcing system integrated with treatment equipment to effectively decompose pollutants. Following this, wastewater is condensed and reclaimed through the recycling system to further reduce the concentration of pollutants in line with the dual goals of pollutant reduction and reuse.
Unit: ppm

Preventive Techniques on Key Pollutants of Wastewater Quality
and Improvement Achievements

Item Status in
2019		 Standards Set by Science
Park Administration		 Targets in
2025		 2019 Improvement Outcome (2014 as Baseline) Preventive Techniques
TMAH 7.86 HSP: 30
CTSP: 20
STSP: 60 		1.0 Reduced by 74% from the previous year
  • Recycle low-concentration liquid waste
  • Establish anion exchange resin towers
Copper ion 0.09 HSP: 1
CTSP: 0.8
STSP: 1.5 		0.1 Reduced by 76% from the previous year(Achieved 2025 goals ahead of schedule)
  • Distribute copper-containing liquid waste and electroplating
NH4-N 17.31 HSP: 30
CTSP: 20
STSP: 60 		20 Reduced by 89% from the previous year(Achieved 2025 goals ahead of schedule)
  • Expand ammonia treatment systems
  • Upgrade treatment facilities and improve treatment efficiency
Chemical oxygen demand 185.5 HSP: 500
CTSP: 500
STSP: 450 		100 Reduced by 54% from the previous year
  • Implement combustion treatment in strippers (Under assessment and planning)
  • Establish biological treatment systems (bioprocess) (Under assessment and planning)

For more information, please read TSMC 2019 Corporate Responsibility Report:

Green Manufacturing - Water Management

Read Full Article