目標：回收水之水質為重要議題。本文為國內首次大規模針對中小學校雨水及中水回收水體之水質調查。方法：以教育部補助設置雨水及中水回收90校永續校園為例，遴選有效樣本34例，包含純收雨水23例、併收雨中水9例、純收中水2例，分別進行大腸桿菌群、化學項目及物理項目等水質檢測。結果：純回收雨水樣本，水質明顯優於併收雨中水的樣本，整體有65%符合飲用水水源取用標準，僅9%能符合沖廁用水基準。在化學項目及物理項目檢測上，分別有26%及12%之水質未能符合環保署訂定之標準。而大腸桿菌群和總有機碳的相關呈顯著。結論：多數學校以屋頂面且不設置任何過濾之方式收集雨水，以應噴灌或飲用水水源取用，然多數水質均未能符合沖廁用途基準。

Objectives: The quality of harvested water is a public health concern. This study is the first large-scale investigation of the harvested rain water and grey water collected on campuses. Methods:The Ministry of Education has subsidized 90 sustainable campuses. We selected 34 eligible
sites for this field investigation. Among them, 23 harvested only rainwater; 9 harvested both rainwater and grey water; and 2 harvested only grey water. Samples were collected for water quality analyses including tests for Escherichia coli, chemicals and physical characteristics. Results:The quality of rain water was obviously better than that of grey water. Approximately 65%of the samples met the standards for drinking water. Only 9% of samples were adequate for flushing a toilet. On chemical and physical analyses, 26% and 12% of the samples, respectively, did not conform to the standards of theEnvironmental Protection Administration. There was a significant
association between the measurements of Escherichia coli and total organic carbon. Conclusions:Most of the schools collected rainwater on the roof without filtration. This was adequate for use as sprinkling water or as drinking water. Most of collected water samples did not qualify for use in flushing toilets.