CWTC primarily uses tap water for wet processing (plating), cleaning and environmental protection purposes. The water sources for each plant are from surface water supplied by third parties, with all sources being freshwater (≤1,000 mg/L total dissolved solids). The water supply for the Taiwan plants comes from the Taiwan Water Corporation, specifically the Gaoping River Weir, Nanhua Interconnecting Pipeline, and Fengshan Reservoir; the plants in China receive water from the Minjiang River and Taihu Lake, while the overseas plants source water from the Selangor River. None of these raw water sources are classified as national or international nature reserves, nor do they come from sensitive water bodies. Additionally, based on the AQUEDUCT WATER RISK ATLAS, the water risk assessment for each plant indicates that the plants in China are rated as "High-Medium risk (3-4)" due to water stress, while all other locations are classified as "Low-Medium risk (1-2)" and are not considered water-stressed areas.
CWTC primarily uses tap water for wet processes (electroplating), cleaning, and environmental protection purposes. Facing global climate change in recent years, to ensure that the plants do not encounter immediate water shortage crises due to a lack of water resources, the Company continuously implements water consumption monitoring and actively promotes water-saving measures across its plants. Starting in 2021, the Taiwan plants installed additional process recycling systems to treat, filter, and reuse rinsing water containing high acid concentrations, replacing direct discharge after wastewater treatment plant processing, thereby improving process wastewater recycling rates and working in conjunction with various water-saving measures to reduce water resource consumption. Furthermore, the Company closely monitors government water condition disclosures; during periods of water scarcity or restrictions, non-essential water use will be prioritized for reduction based on water conditions, and the proportion of process recycled water used will be increased to minimize the impact of water restrictions on production operations and maintain the stability of plant water supply and production operations.
In 2025, increased production capacity drove water withdrawal up to 1,491 million liters (+8.36%); however, this growth rate remained lower than the increase in production volume (+9.88%), indicating continuous improvement in water use efficiency. The water recycling rate also rose from 27.69% to 27.83%, demonstrating the effectiveness of water conservation management.
In 2021, the Taiwan plants installed recycling systems where process water is recycled for reuse through ultrafiltration (UF) and reverse osmosis (RO) processes. In 2022, we adopted membrane bioreactors (MBR), Membrane Chemical Reactor (MCR) devices to replace the UF system. The enlarged membrane pore size increased fluxes and improved the fouling issue, enhancing the efficiency of the water recycling system. At the same time, the switch reduced the frequency of backflushing and chemical cleaning and consequently the consumption of recycled water. Additionally, the less frequent replacement of filter bags led to waste reductions. Since 2022, MBR systems have been progressively added, with the third MBR system completed in 2025. The daily amount of recycled water increased from 170 tons in 2023 and 181 tons per day in 2024 to a daily average of 224 tons recycled to the industrial water pool in 2025, demonstrating significant results. Plans are in place to install a fourth MBR system in 2026.
The Taiwan plants expanded their process water recycling system in 2021 by adding a pure water recovery system. The concentrated water produced by the RO pure water system is further treated through a secondary reverse osmosis (RRO) for reuse in the manufacturing process. Due to the 2B3T pretreatment design of the RO pure water system, the quality of the concentrated water from the secondary RRO system is even better than tap water, enabling its recycling and reuse in the industrial water pool. In 2025, the total volume of ultrapure water recovered from processes at the Taiwan plants reached 82,867 metric tons, accounting for 11.4% of total water usage.
Electroplating equipment adopts the counter-current rinsing design where the rinse water is circulated through three washing tanks, achieving water conservation.
CWTC conducts regular annual sampling and testing of various parameters in the effluents to ensure that wastewater generated from the manufacturing processes fully complies with the current environmental laws and regulations and the standards of the industrial park management, thereby minimizing environmental pollution impact. We are proactively reviewing and improving the wastewater pollution control systems at our plants. In 2023, the test results of effluents discharged from all plants remained in compliance with the regulatory standardsNote approved in their respective locations.
Note : The Taiwan plants adhere to the “Standards for Wastewater Discharge into Sewerage Systems of Nanzih Technology Industrial Park, Kaohsiung.” The China plants comply with the “Integrated Wastewater Discharge Standard,” the “Water Quality Standards for Discharge to Municipal Sewers,” and the “Discharge Standards of Pollutants for Electroplating.” The overseas plants follow Malaysia’s “Environmental Quality Act 1974.”