Source Reduction – Raw Materials Usage Reduction
TSMC seeks to optimize processes to minimize raw material use and waste production, protecting the environment while reducing costs at the same time. TSMC has a designated unit that periodically reviews raw materials reduction performance. Internally, we optimize our process recipe for raw material usage, which can not only reduce production cost but also reduce the generation of pollutants and wastes. Externally, we require our process tool suppliers to review and minimize the chemical usage step by step. In 2015, TSMC TSMC formed a cross-organization waste management taskforce co-led by the Senior VP of Material Management and Risk Management and a VP of Operations to promote company-wide waste reduction projects and conduct periodical review.
Water Pollution Control
TSMC's water pollution control strategy is first to reduce pollutants in process wastewater, followed by water recycling and treatment of pollutants in water. Effluent water quality must be better than or compliant with governmental standards.
TSMC's major water-using process is an ultra-pure water system which turns raw water into ultra-pure water mainly used in process tools for cleaning chemical residue on wafer surfaces. To reduce total water usage, TSMC's effluent water from ultra-pure water systems and process tools are graded by purity. The cleanest is reused in the manufacturing process; the second grade taken from the recycling treatment is employed in secondary uses such as cooling-tower water. Wastewater that cannot be recycled is discharged to treatment facilities for final wastewater treatment.
TSMC adopts a strict front-end wastewater categorization strategy to improve treatment efficiency. Wafer fabs' wastewater can be divided into fluoride, copper, general acid, and various polishing wastewaters. All kinds of wastewater are strictly categorized at process tools, and collected to wastewater treatment facilities through separated piping. In order to manage these drains strictly, there are more than 20 categories of drainage types, carefully operated and maintained by professional teams to comply with the standards of the Science Park Administration (SPA). The water is then discharged to the SPA wastewater treatment plant for further treatment after professional teams ensure the discharge complies with SPA standards. The treated wastewater is discharged to rivers from the SPA's wastewater treatment plants in compliance with river discharge standards. The SPA also conducts random measurement of the discharges of each company in Science Park.
TSMC operates only after ensuring that the environment will not be polluted. Each fab is equipped with effective wastewater treatment systems including complete backup systems, such as emergency power supplies, to reduce the likelihood of abnormal discharge. Operating status of all of TSMC wastewater treatment systems are monitored 24 hours a day by shift personnel. If operating conditions diverge from the preset limits, a warning signal is sent and wastewater discharge is halted. Data gathered for monitoring system effectiveness have been designated an important tracking item to ensure effluent quality.
Developing New Technologies to Response to New Regulations
In addition to complying with SPA standards, TSMC continually works with industries and universities to improve discharge quality in areas such as COD (Chemical Oxygen Demand), TMAH (Tetra-methyl ammonium hydroxide) and NH3-N to reduce hazards to water bodies.
In addition, TSMC continues to explore new wastewater treatment and chemical recycling technologies. For example, TSMC led the industry in performing a series of experiments to obtain the optimal processing technology for phosphorus acid wastewater recycled by external contractors and high-concentration hydrogen peroxide on-site reuse, which attests to our dedication to protect the environment.
Starting from 2015, TSMC led the development wafer fab wastewater recycling technology and successfully completed a pilot plant test by using Advanced Oxidation Process (AOP) combining Reverse Osmosis and ion-exchanging methodologies. The water treated by the pilot plant can be reused by wafer fabs. We will conduct continuous operation and use the wastewater effluent from the wastewater treatment plant of the Science Park for a pilot plant test in the near future.
Air Pollution Control
TSMC's air pollution control strategy is to optimize process to reduce pollutants in air exhaust, and then to abate pollutants in air exhaust through high-efficiency equipment to comply with or surpass legal requirements. Air pollutant concentrations in TSMC's exhaust are far below the standards required by Taiwan's EPA, according to actual measurements performed over the years.
Wafer fabs emit three major types of exhaust: acid exhaust, base exhaust, and volatile organic compounds. Heat exhaust emitted by process equipment does not cause air pollution. Air pollution control systems depend on various categories and characteristics of pollutants. TSMC installs local scrubbers behind process tools in order to treat toxic, flammable and PFC gases. First, high temperatures or other physical and chemical measures are used to significantly reduce the concentration of pollutants in tool exhaust. The gas is then inducted to central waste gas treatment equipment for end-point treatment. Endpoint treatment includes zeolite-rotary-wheel absorbing equipment for volatile organic compounds (VOC) treatment and wet scrubber equipment for acid or base gases.
The performance of all TSMC fabs, including overseas facilities, is fully compliant or exceeds the air pollutant emissions standards in the areas where they operate. TSMC has deployed high-performance air pollution control equipment with at least N+1 backup systems so that all pollution control equipment can continue waste gas control 24 hours a day, 365 days a year in case of equipment breakdown. Operational status of all TSMC air pollution control systems is monitored 24 hours a day by shift personnel. Data collected by system efficiency monitoring have been classified as an important tracking item in order to ensure air exhaust quality. In 2009, we added an electronic quarterly air pollution report system that can automatically confirm the accuracy of declarations.
To ensure normal equipment operations and reduce abnormal pollutant emissions, TSMC has installed backup systems, including power generation, to back up malfunctions of operation equipment. TSMC has also installed backup fuel supply systems for VOC pollution control equipment that will engage if the original fuel supply systems experience difficulties.
Waste Reduction and Resource Recycling
TSMC has transitioned from traditional waste cleaning and disposal to integrated resource management, and has a designated waste resources management unit to treat waste as valuable resources to be recycled as much as possible. In order to sustainably use our resources, the first priority of our waste management is reduction; the second is material recycling, followed by energy recovery, and finally disposal through incineration and landfill.
In 2015, TSMC established on-site pre-treatment systems for waste sulfuric acid, which is reused in our wastewater treatment system. This action greatly reduces the usage of raw acids and supports our goal of zero waste. TSMC carefully selects waste disposal and recycling contractors and performs annual audits of certification documents and site operations. In order to monitor waste disposal activities, TSMC also adopts proactive actions to strengthen vendor auditing effectiveness. For example, all waste transportation contractors are requested to join the "GPS Satellite Fleet" so that all transportation routes and abnormal stays for all trucks can be traced ( All contractors joined the system in 2015 ).
In addition, all waste recycling and treatment vendors install CCTV in operation sites for the purpose of review and auditing in tracing waste receiving and handling status. In addition, TSMC has strengthened the tracking of flows of recycled product to ensure the appropriate reuse of the product. All these actions are to ensure legal and proper recycling and treatment of wastes. TSMC initiated a "Waste Disposal Vendor Assessment Standard" with its technology industry partners. This standard was announced in 2016, and expected to leverage the power of industry members to upgrade the overall quality of the waste disposal industry.