To address the increasingly uneven rainfall patterns in Taiwan in recent years, PSMC has optimized processes and invested in equipment to enhance water recovery rates and process water efficiency. In 1996, it became the first semiconductor company in the Hsinchu Science Park to commit to a process water recovery rate of more than 85%. The process water recovery rate in 2024 has reached an average of 88%, which has reached the set water recovery rate target of 85%, and the water volume of the 12-inch factory is controlled below 95% of the permitted water consumption.

The manufacturing process wastewater from all of our plants is treated in our wastewater treatment plant before being discharged into the wastewater treatment plant in the Science Park for subsequent treatment and discharge. In order to grasp the effectiveness of the treatment of different components, a total of 30 different water systems, including recoverable and non-recoverable, are diverted for treatment according to the different characteristics of the discharge liquid at the manufacturing end, such as type, concentration, and conductivity. Some waste acids (phosphoric acid/copper sulfate/sulfuric acid/ ammonium hydro fluoride/ammonium fluoride) and organic waste liquids (isopropyl alcohol/photoresist/de-photoresist/photographic solution) still have economic value for recovery, Also having separate diversions can not only reduce the amount of dosing in the wastewater plant, but can also reduce the difficulty of waste treatment at the backend and the burden on the environment. PSMC have pH and Fion testing equipment installed in our effluent process, and the Hsinchu Science Park Administration conducts sampling tests on effluent quality twice a month to strictly control the effluent quality of our plants, and to prioritize the management of effluent quality in accordance with plant regulations. In recent years, the annual average test values of the effluents from each plant have been far lower than with the Science Park's standard of control, and there have been no incidents of non-compliance with the effluent value limits.

The recycled water from the manufacturing process is treated by the appropriate recycled water system and then returned to the pure water system for reuse to increase the recovery rate. For high concentrations of unrecoverable wastewater, it is discharged to the wastewater treatment system (including acid-alkali, fluoric acid, grinding, and ammonia nitrogen wastewater treatment system) and then piped into the wastewater treatment plant at the Science Park for subsequent treatment and discharge, so our effluent is not directly discharged into rivers and bodies of water, and has no direct impact on bodies of water and related habitats. There has also been no serious leakage of wastewater from any of the PSMC plants over the years, and there have been no major fines.

In order to ensure the environmental safety of the Science Park, the Company has installed overflow prevention dikes and flood pumps at the perimeter of each plant, and flood pumps at the ground floor of each building. In the event of an abnormal leak or heavy rainfall, the flood pumps will pump the water to the wastewater treatment plant for treatment and then discharge it to the sewage drain in the Science Park. In addition, chemical tanker filling areas are equipped with overflow prevention ditches to prevent chemicals from leaking and polluting the environment. In the stormwater drains of the high-risk areas, abnormal event drainage pumps are also installed to pump abnormal sewage back to the wastewater treatment plant for treatment in order to prevent pollution incidents. All relevant measures are in accordance with the Company's internal stormwater drainage practices.