From June 1990 to April 1991, irregular surveys were conducted at management stations, police regiments, streams often used by tourists, and lakes and swamps in the western part of the Yushan National Park. In addition, monitoring was conducted at the only farm in the park, Salihsian Trout Farm, where water from the farm is released. Water samples from the farm were taken to the former Central Environmental Protection Center, Department of Provincial Environmental Protection for testing. Test results showed that no acidification of the water from the rivers, lakes and swamps had occurred. Also, the water quality was good. Only at the Meishan Lodge and Dashuiku was the water less suitable for drinking.

At Batongguan, the poisonous metal cadmium slightly exceeded the normal limits, and an investigation of its source should be conducted. The water released from the Salihsian Trout Farm meets the legally required standard, and there shouldn’t be concerns about it contaminating the surrounding water sources.