The purpose of this project was to examine the water quality of the pre-chosen 362 drinking water systems and 38 simple tap-water systems of the 22 municipal counties or cities. There were 71 analytes for drinking water systems, with 47 of them regulated and the remaining 24 non-regulated. 　　The regulated analytes included 13 metals (arsenic, lead, selenium, chromium, cadmium, barium, antimony, nickel, mercury, silver, indium, molybdenum and aluminum), 1 health affecting substance (cyanide), 4 disinfection byproducts (total trihalomethanes (TTHMs), bromate, chlorite and haloacetic acids (HAA5) ), 15 volatile organics (trichoroethylene, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dichloroethane, vinyl chloride, benzene, 1,4-dichlorobenzene, 1,1-dichloroethene, dichloromethane, 1,2-dichlorobenzene, xylenes, cis- and trans- 1,2-dichloroethene, tetrachloroethene and toluene), 13 pesticides (endosulfan, lindane, butachlor, 2,4-D, paraquat, methomyl, carbofuran, Isoprocarb, methamidophos, diazinon, parathion, EPN, and monocrotophos) and 1 persistent volatile organic compound (dioxins), which accounted for a total of 47 analytes. 　　The non-regulated analytes included 3 metals (hexavalent chromium, gallium, thallium), 3 disinfection byproducts (dichloroacetonitrile, dibromoacetonitrile and chloral hydrate), 7 volatile organics (1,1-dichloroethane, 1,2-dichloro propane, styrene, chlorobenzene, ethylbenzene, formaldehyde and MTBE), 8 endocrine disrupting chemicals (nonyl phenols, bisphenol A, dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), nenzyl butyl phthalate (BBP), di-n-octyl phthalate (DNOP), bis(2-ethylhexyl) phthalate (DEHP) ), 2 microorganisms (fecal coliforms, E. coli) and 1 biological metabolite (microcystin-LR), which accounted for a total of 24 analytes. 　　The total test counts of the regulated analytes and non-regulated analytes for tap-water systems were 6,025 and 1,350, and the total test counts of the regulated and non-regulated analytes for simple tapwater systems were 513 and 81, respectively. The 2015 analytical results indicated that silver, mercury, indium, cyanide, bromate, chlorite, trichoroethylene, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dichloroethane, vinyl chloride, benzene, 1,4-dichlorobenzene, 1,1-dichloroethene, dichloromethane, 1,2-dichlorobenzene, xylenes, cis- and trans- 1,2-dichloroethene, tetrachloroethene and toluene, endosulfan, lindane, butachlor, 2,4-D, paraquat, methomyl, carbofuran, Isoprocarb, methamidophos, diazinon, parathion, EPN, and monocrotophos in drinking water supply 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 sample TTW-I10 in Chang-hua County (Yuan-lin second water treatment plant) and TTW-O21 in Kaohsiung City (Lu-jhu water treatment plant), which had a passing rate of 96.4% and 97.1%. (The proportion of analyses passing the drinking water regulatory limits was calculated by dividing the number of analyses in compliance with the limits by the total number of analyses. Cases absolved by statement or appeal were not excluded from the calculation.) All analytes tested met the required drinking water criteria except lead and HAA5, which had a passing rate of 99.8% and 99.1%. All other non-regulated analytes were less than the method detection limits or quantitation detection limits except formaldehyde, dichloroacetonitrile, dibromoacetonitrile, chloral hydrate, fecal coliforms and E. coli. 　　Test locations meeting any of the following criteria were selected for follow-up and re-tested in September to October: 1) analytes that exceeded or approached the drinking water regulatory limits during either 2014 or April to August this year, 2) aluminum concentrations exceeding 0.2 mg/L, or 3) results exceeding the historical maxima. The results indicated that the analytes re-tested met the drinking water quality standards except for aluminum of TTW-G02 in Taichung City (Feng-yuan second water treatment plant), TTHMs of TTW-T30 in Taitung County (Green Island water treatment plant), and HAA5 of TTW-F09 in Miaoli County (Ming-de water treatment plant), which still exceeded the alarm value (70% of the drinking water criteria). However, the test locations of Lu-jhu water treatment plant in Kaohsiung City still exceeded the drinking water regulatory limits for HAA5 at this stage.

Drinking Water Quality Standards, Total Trihalomethane, Heavy Metals