The purpose of this project was to examine the water quality of the pre-chosen 364 drinking water systems and 38 simple tap-water systems of the 22 municipal counties (or cities). The analytes being tested included heavy metals (arsenic, lead, selenium, chromium, cadmium, barium, antimony, nickel, mercury and silver), total trihalomethanes (TTHMs), bromate, volatile organics (trichoroethylene, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dichloroethane, vinyl chloride, benzene, 1,4-dichlorobenzene, and 1,1-dichloroethene; a minimum of 216 to be analyzed of the 402 systems) and pesticides (endosulfan, lindane, butachlor, 2,4-D, paraquat, methomyl, carbofuran, MIPC, methamidophos, diazinon, parathion, EPN, and monocrotophos; a minimum of 120 to be analyzed of the 402 systems ), which accounted for a total of 12 to 33 analytes. In addition, one waterworks is to be chosen from each of the 22 municipal districts for the analyses of cyanide, indium, molybdenum, dioxins and other analytes on top of the list to be regulated (hexavalent chromium, gallium, thallium, aluminium, vanadium, haloacetic acids, dichloromethane, 1,1-dichloroethane, 1,2-dichloropropane, 1,2-dichlorobenzene, xylenes, styrene, cis- and trans- 1,2-dichloroethene, tetrachloroethene, chlorobenzene, toluene, ethylbenzene, nonyl phenols, bisphenol A, bis(2-ethylhexyl) phthalate and microcystin-LR). The water quality examinations were completed for 364 drinking water systems and 38 simple tap water systems in the year of 2012. The total test counts of the regulated analytes and potentially regulated analytes for drinking water systems were 7737 and 601, respectively, while the total test counts of the regulated analytes for simple tap-water systems were 456. The analytical results from 2012 indicated that trichloroethene, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dichloroethane, vinyl chloride, benzene, 1,4-dichlorobenzene, 1,1-dichloroethene, endosulfan, lindane, butachlor, 2,4-D, paraquat, methomyl, carbofuran, MIPC, methamidophos, diazinon, parathion, EPN, and monocrotophos in drinking water supply systems, and bromate, mercury and bromoform in simple tap-water systems were not detected or less than the quantitation detection limits of the respective analytical methods. Water examined for all tested locations met the required drinking water criteria except samples TTW-G09 in Tai-Chung city (Ku-Kuan water purification plant) and TTW-H13 in Nan-Tou county (Hsin-Yi water purification plant), which had a passing rate of 93.8% and 95.0%, respectively. All analytes tested met the required drinking water criteria except bromate and TTHMs, which had a passing rate of 99.7%. Besides aluminium, all other potentially regulated analytes were less than the method detection limits or quantitation detection limits. The test locations with analytes whose concentration exceeded the drinking water regulatory limits in the first stage of 2012 and those with the highest historical results were followed up and re-tested in October this year. The results indicated that all analytes re-tested met the drinking water quality standards.

Drinking Water Quality Standards, Total Trihalomethane, Heavy Metals