This project reviewed the drinking water management regulation and respondences to extreme climate of other countries and international organization. The risk of asbestos in drinking water in Taiwan was also evaluated. This project implemented contaminants screening process of drinking water quality regulation. Six unregulated estrogenic steroids were selected for evaluation. Their concentration was monitored in six representative drinking water treatment plants, and their health risk in drinking water system in Taiwan were evaluated. Results indicated that there is no significant risk of these 6 compounds on drinking water in Taiwan. This project also collected the monitoring histories of unregulated contaminants in Preliminary Contaminant Candidate List and Contaminant Candidate List, and proposed unregulated contaminants monitoring suggestions. In addition, this project inspected 28 unregulated compounds of emerging concern in drinking water. There were 13 compounds with monitoring results all below detection or quantification limitation. The other compounds with detection values were at very low concentration level. There were only few samples with higher concentration on germanium, thallium, boron,2-MIB, and per- and polyfluorinated chemicals (PFCs). It is suggested to monitor them continuously. Besides, this project evaluated 6 different microbial indicators at 20 sample point when water re-supply after water outage. It is suggested to monitor those indicators to accumulate more data for evaluating if we should modify the microbial indicators standard.