Comparison of TWD's Tap Water Quality with U.S., Japan, E.U., W.H.O.'s Guidelines, and Water Quality Standards of EPA, R.O.C.
Microbial Parameters | ||||||
| Parameters | TWD Tap Water Quality | Maximum Contaminant Level | ||||
| Taiwan (2018) | U.S. (2012) | Japan (2015) | E.U. (2015) | W.H.O. (2011) | ||
| 1.Total Coliforms (CFU/100ml,MPN/100ml) | <1 | 6 | 5.0% ＊1*2 | 0*3 | 0 | 0 |
| 2.Total Bacterial Count (CFU/ml) | <1 | 100 | - | 100 | *4 (22˚C) | 0 |
Unit : mg/L (unless specified otherwise)
Maximum Contaminant Level Goal（MCLG）：The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
*1.No more than 5.0% samples total coliform-positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month.)
*2. Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animals wastes.
*3. Drinking water standard of Japan set E-coli only.
*4. Acceptable to consumers and no abnormal change.
Maximum Contaminant Level Goal（MCLG）：The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
*1.No more than 5.0% samples total coliform-positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month.)
*2. Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animals wastes.
*3. Drinking water standard of Japan set E-coli only.
*4. Acceptable to consumers and no abnormal change.
Physical Parameters | ||||||
| Parameters | TWD Tap Water Quality | Maximum Contaminant Level | ||||
| Taiwan (2018) | U.S. (2012) | Japan (2015) | E.U. (2015) | W.H.O. (2011) | ||
| 1.Odor (TON) | 1 | 3 | 3＊5 | *4 | *4 | *4 |
| 2.Turbidity (NTU) | 0.18 | 2 | TT＊6 | 2 | *4 | 1.5 |
| 3.Color (Pt-Co units) | 2 | 5 | 15＊5 | 5 | *4 | 5 |
Unit : mg/L (unless specified otherwise)
NTU = nephelometric turbidity unit.
*5. National Secondary Drinking Water Regulations (NSDWRs or secondary standards)
*6. TT :Treatment technique required
NTU = nephelometric turbidity unit.
*5. National Secondary Drinking Water Regulations (NSDWRs or secondary standards)
*6. TT :Treatment technique required
Chemical Parameters | |||||||||||||
| Parameters | TWD Tap Water Quality | Maximum Contaminant Level | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Taiwan (2018) | U.S. (2012) | Japan (2015) | E.U. (2015) | W.H.O. (2011) | |||||||||
(A) Substances affecting health | |||||||||||||
| 1. Arsenic (As) | ND （< 0.00079） | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | |||||||
| 2. Lead (Pb) | ND （< 0.00064） | 0.01 | 0.015＊7 | 0.01 | 0.01 | 0.01 | |||||||
| 3. Selenium (Se) | ND （< 0.00154） | 0.01 | 0.05 | 0.01 | 0.01 | 0.01 | |||||||
| 4. Chromium (Cr) | ND （< 0.00022） | 0.05 | 0.1 | 0.05 (Cr6+) | 0.05 | 0.05 | |||||||
| 5. Cadmium (Cd) | ND （<0.00042） | 0.005 | 0.005 | 0.003 | 0.005 | 0.003 | |||||||
| 6. Barium (Ba) | 0.006 （<0.00045） | 2.0 | 2.0 | - | - | 0.7 | |||||||
| 7. Antimony (Sb) | ND （<0.00073） | 0.01 | 0.006 | - | 0.005 | 0.02 | |||||||
| 8. Nickle (Ni) | ND （< 0.00023） | 0.07 | - | - | 0.02 | 0.07 | |||||||
| 9. Mercury (Hg) | ND （< 0.00008） | 0.002 | 0.002 | 0.0005 | 0.001 | 0.006 | |||||||
| 10.Cyanide (CN-) | ND （< 0.003） | 0.05 | 0.2 | 0.01 | 0.05 | - | |||||||
| 11.NO- 2-N (Nitrite Nitrogen, as N) | ND （< 0.0005） | 0.1 | 1 | 0.04 | 0.1 | 3 | |||||||
| Disinfection by-product | |||||||||||||
| 12.Trihalomethanes (THMs) | 0.0051 | 0.08 | 0.08 | 0.1 | 0.1 | *8 | |||||||
| 13. Haloacetic acids (sum of concentrations of Monochloroacetic acid(MCAA), Dichloroacetic acid, Trichloroacetic acid(DCAA), Monobromoacetic acid(MBAA) & Dibromoacetic acid(DBAA)) | 0.00603 | 0.060 | 0.06 | 0.02 (MCAA) 0.03(DCAA) 0.03(TCAA) | - | 0.02 (MCAA) 0.02(TCAA) | |||||||
| 14. Bromate | ND （<0.00045） | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | |||||||
| 15. Chlorite | ND （<0.00082） | 0.7 | 1 | - | - | 0.7 | |||||||
| Volatile Organics | |||||||||||||
| 16.Trichloroethylene | ND （<0.000028） | 0.005 | 0.005 | 0.01 | *10 | 0.02 | |||||||
| 17.Carbon Tetrachloride | ND （<0.000031） | 0.005 | 0.005 | 0.002 | - | 0.004 | |||||||
| 18.1,1,1-Trichloroethane | ND （<0.000023） | 0.20 | 0.20 | 0.06 | - | - | |||||||
| 19.1,2-Dichloroethane | ND （<0.000036） | 0.005 | 0.005 | - | 0.003 | 0.03 | |||||||
| 20.Vinyl chloride | ND （<0.00033） | 0.0003 | 0.002 | - | 0.0005 | 0.0003 | |||||||
| 21.Benzene | ND （<0.0003） | 0.005 | 0.005 | 0.01 | 0.001 | 0.01 | |||||||
| 22.Para-Dichlorlbenzene | ND （<0.000028） | 0.075 | 0.075 | - | - | 0.3 | |||||||
| 23.1,1-Dichloroethylene | ND （<0.000028） | 0.007 | 0.007 | 0.04 | - | - | |||||||
| 24. Dichloromethane | ND (<0.00062) | 0.02 | 0.005 | 0.02 | - | 0.02 | |||||||
| 25. 1,2-Dichlorobenzene | ND (<0.00035) | 0.6 | 0.6 | - | - | 1 | |||||||
| 26. Toluene | ND (<0.00036) | 0.7 | 1 | - | - | 0.7 | |||||||
| 27. Xylenes | ND (<0.000072) | 0.5 | 10 | - | - | 0.5 | |||||||
| 28. cis-1,2-Dichloroethene | ND (<0.00003) | 0.07 | 0.07 | 0.04*9 | - | - | |||||||
| 29. trans-1,2-Dichloroethene | ND (<0.000023) | 0.1 | 0.1 | 0.04*9 | - | - | |||||||
| 30. Tetrachloroethene | ND (<0.000032) | 0.005 | 0.005 | 0.01 | *10 | 0.04 | |||||||
| Pesiticides | |||||||||||||
| 31.Endosulfan | ND （<0.000003） | 0.003 | - | - | *12 | - | |||||||
| 32.Lindane | ND （<0.0000019） | 0.0002 | 0.0002 | - | *12 | 0.002 | |||||||
| 33.Butachlor | ND （<0.00024） | 0.02 | - | - | *12 | - | |||||||
| 34.2.4-Dichlorooxyacetic acid | ND （<0.00017） | 0.07 | 0.07 | - | *12 | 0.03 | |||||||
| 35.Paraquat*11 | ND （<0.0044） | 0.01 | - | - | *12 | - | |||||||
| 36.Methomyl | ND （<0.00239） | 0.01 | - | - | *12 | - | |||||||
| 37.Carbofuran | ND （<0.00236） | 0.02 | 0.04 | - | *12 | 0.007 | |||||||
| 38.Isoprocarb | ND （<0.00249） | 0.02 | - | - | *12 | - | |||||||
| 39.Methamidophos | ND （<0.00255） | 0.02 | - | - | *12 | - | |||||||
| 40.Diazinon | ND （<0.00000144） | 0.005 | - | - | *12 | - | |||||||
| 41.Parathion | ND （<0.0000026） | 0.02 | - | - | *12 | - | |||||||
| 42.EPN | ND （<0.0000119） | 0.005 | - | - | *12 | - | |||||||
| 43.Monocrotoohos | ND （<0.0000478) | 0.003 | - | - | *12 | - | |||||||
| Persistent organic pollutants, POPs | |||||||||||||
| 44. Dioxin (pg WHO-TEQ/L) | 0.002 | 3 | 3 | - | - | - | |||||||
(B) Substances probably affecting health | |||||||||||||
| 1.Fluoride (F-) | 0.04 | 0.8 | 4.0*13 | 0.8 | 1.5 | 1.5 | |||||||
| 2.NO3-N (Nitrate Nitrogen ,As N) | 0.67 | 10.0 | 10.0 | 10 | 50 | 50 | |||||||
| 3.Silver (Ag) | ND （<0.00041） | 0.05 | 0.1*5 | - | - | - | |||||||
(C)Substances affecting palatability | |||||||||||||
| 1.Iron (Fe) | 0.001 | 0.3 | 0.3*5 | 0.3 | 0.2 | 0.1 | |||||||
| 2.Manganese (Mn) | 0.002 | 0.05 | 0.05*5 | 0.05 | 0.05 | 0.05 | |||||||
| 3.Copper (Cu) | ND （<0.00056） | 1.0 | 1.0*5 1.3*7 | 1.0 | 2.0 | 2.0 | |||||||
| 4.Zinc (Zn) | 0.002 | 5.0 | 5.0*5 | 1.0 | - | - | |||||||
| 5.Sulfate (SO4-2) | 10.1 | 250 | 250*5 | - | 250 | - | |||||||
| 6.Phenols | ND （<0.0009) | 0.001 | - | 0.005 | - | - | |||||||
| 7.MBAS (Anionic Surfactant, Methylene Blue Activated Substance) | ND （<0.03） | 0.5 | - | 0.2 | - | - | |||||||
| 8.Chloride (Cl-) | 7.8 | 250 | 250*5 | 200 | 250 | - | |||||||
| 9.NH3-N (Ammonia Nitrogen, As N) | ND （<0.011） | 0.1 | - | - | 0.5 | - | |||||||
| 10.Total Hardness*14, as CaCO3 | 37.5 | 300 | - | - | - | - | |||||||
| 11.Total Dissolved Solids | 65 | 500 | 500*5 | 500 | - | - | |||||||
| 12. Aluminium (Total Al) | 0.051 | 0.3 | 0.05~0.2*5 | 0.2 | 0.2 | 0.1 | |||||||
D. Residual chlorine | 0.58 | 0.2~1.0 | 4 | - | - | 0.5-1.5 | |||||||
E. pH value | 7.2 | 6.0~8.5 | 6.5~8.5 *5 | 5.8~8.6 | 6.5~9.5 | 8.2~8.8 (25˚C) | |||||||
ND : Non detected.
Unit : mg/l (unless specified otherwise)
*7. Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 0.015 mg/L.
*8. The sum of the ratio of the concentration of each to its respective quideline value should not exceed 1.
*9. The sum of concentration of cis-1,2-Dichloroethene and trans-1,2-Dichloroethene should not exceed 0.04 mg/L.
*10. Sum of concentrations of Tetrachloroehtene and Trichloroethene should not exceed 0.01 mg/L.
*11. paraquat (as dichloride), quivalent to 0.007 mg/L for paraquat ion.
*12 . Pesticides,each 0.0001 mg/L ,Total: 0.0005 mg/L.
*13. USEPA also set the SMCL(Secondary Maximum Contaminant Limits)as 2 mg /L for fluoride Public acceptance of hardness varies considerably.
*14. Generally, hardness levels between 80 and 100 mg/L (as CaCO3 ) are considered acceptable; levels greater than 200 mg/L are considered poor but can be tolerated; those in excess of 500 mg/L are normally considered unacceptable.
Unit : mg/l (unless specified otherwise)
*7. Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 0.015 mg/L.
*8. The sum of the ratio of the concentration of each to its respective quideline value should not exceed 1.
*9. The sum of concentration of cis-1,2-Dichloroethene and trans-1,2-Dichloroethene should not exceed 0.04 mg/L.
*10. Sum of concentrations of Tetrachloroehtene and Trichloroethene should not exceed 0.01 mg/L.
*11. paraquat (as dichloride), quivalent to 0.007 mg/L for paraquat ion.
*12 . Pesticides,each 0.0001 mg/L ,Total: 0.0005 mg/L.
*13. USEPA also set the SMCL(Secondary Maximum Contaminant Limits)as 2 mg /L for fluoride Public acceptance of hardness varies considerably.
*14. Generally, hardness levels between 80 and 100 mg/L (as CaCO3 ) are considered acceptable; levels greater than 200 mg/L are considered poor but can be tolerated; those in excess of 500 mg/L are normally considered unacceptable.