This plan collected basic data from a total of 893 site-specific monitoring wells; the locations of these wells are mostly in factories, dumping sites, gas stations, and potential contaminated sites. The 356 wells that were established over 2 years and seldom used were re-visited, checked and maintained their functions. Television Inspection system was conducted for 45 of the 356 wells, which were either lack of design detail information or malfunctioning. After the whole assessments, 66 out of 356 wells (7.4%) were confirmed as malfunction and unable conduct sampling process. Groundwater quality analyses were conducted for 113 wells, which were either lack of groundwater quality data or contaminated substances found previously. The results of the analyses showed that the concentrations of some chlorinated-hydrocarbon compounds were higher than the Groundwater Pollution Control Standards. 1,2-Dichloroethane was found in 2 wells located in Linyuan Industrial Area. Trichloroethylene and vinylchloride were found one located in Chien Chin District; another located in Linyun Industrial Area. To establish the “Potential Pollution Zone” in Northern Taiwan, “Two Stages Screening” method was used. First of all, constructed a Possible Potential Pollution Zone List; Secondly, combined the potential polluted index and hydrogeology index to evaluate the pollution degree of each zone and then select the top 20 areas. In analyzing and simulating the “Potential Pollution Zone“, MEMO model was used for planning the locations of new monitoring wells. After evaluating the historical pollution events of the areas, 1 to 4 monitoring wells were suggested in each area cooperating the existing site-specific monitoring wells and regional monitoring wells. As a result, 60 monitoring wells were planned to complete the construction the “Pre-warning Monitoring Well System”.

monitoring well,management and maintain system,Detection monitoring system