The Nanhuang-Hsi stream water is a part of the source of the potable water in YangMingShan National Park. The hot spring owners mingle the stream waters and irrigating waters with acid and hot springs to commercialize for tourists. The purpose of this study is to asses water quality of stream waters, irrigating waters and spring water in Nanhuang-Hsi drainage area for the comsumers， health.The main factors influencing water quality of stream waters are acid gas erupting from Hsiao-yuken fumaroles in Chutzehu area, fertilizer and pesticides discharge from the tourist farms, waste water and sewage effluent from restaurants and residents, trash thrown from tourists and vehicles, acid and hot spring water entering from Din-Peitou and Shuangchung-Hsi, and waste spring water discharging from YangMing-Hsi. The Nanhuang-Hsi stream water is mainly contaminated by human activities, but [ NH4¯], [ PO4-3] and [ NO2¯] are still within safety standard of potable water. High [Si（OH）4 ¯] is released from weathering of andesite in Nanhuang-Hsi drainage. The contaminated heavy metal Pb is released from the replaced pipeline during earthwork construction. The microbial test shows that the green-sulfide spring water of owners is within safety sanitary standard because pH in acid spring water is below 2. The white-spring may be polluted by hot-spring conduit.Exploitation of the limited water resources should be restricted. To maintain sustainable use of water resources, environmental impact should be assessed regularly.
