The wastewater generated at FEIS still retains 70% of moisture content after going through the frame filter, and produces approximately 200 metric tons of sludge per year that require NT$14.85 million in processing fees. Therefore, the plant installed the sludge drying system, which utilizes low-temperature heat pump dryer to avoid waste gas. The outlet is connected to the sludge bag, which captures the small amount of waste gas generated for central processing and emission. This design helps reduce the moisture content in the sludge to less than 30% while conserving energy and protecting the environment. Meanwhile, the sludge drying system further reduces the moisture content to approximately 20%. In 2021, FEIS has reduced waste materials by 10%.