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 | ||||||
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Parameters | TWD Tap Water Quality | Maximum Contaminant Level | ||||
Taiwan (2020) | U.S. (2018) | Japan (2015) | E.U. (2015) | W.H.O. (2017) | ||
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 | ||||||
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Parameters | TWD Tap Water Quality | Maximum Contaminant Level | ||||
Taiwan (2019) | U.S. (2018) | Japan (2015) | E.U. (2015) | W.H.O. (2017) | ||
1.Odor (TON) | 2 | 3 | 3*5 | *4 | *4 | *4 |
2.Turbidity (NTU) | 0.10 | 2 | TT*6 | 2 | *4 | - |
3.Color (Pt-Co units) | 2 | 5 | 15*5 | 5 | *4 | - |
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 | |||||||||||||
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Parameters | TWD Tap Water Quality | Maximum Contaminant Level | |||||||||||
Taiwan (2019) | U.S. (2018) | Japan (2015) | E.U. (2015) | W.H.O. (2017) | |||||||||
(A) Substances affecting health | |||||||||||||
1. Arsenic (As) | ND (< 0.0012) | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | |||||||
2. Lead (Pb) | ND (< 0.0007) | 0.01 | 0.015*7 | 0.01 | 0.01 | 0.01 | |||||||
3. Selenium (Se) | ND (< 0.0010) | 0.01 | 0.05 | 0.01 | 0.01 | 0.04 | |||||||
4. Chromium (Cr) | ND (< 0.0004) | 0.05 | 0.1 | 0.05 (Cr6+) | 0.05 | 0.05 | |||||||
5. Cadmium (Cd) | ND (<0.0005) | 0.005 | 0.005 | 0.003 | 0.005 | 0.003 | |||||||
6. Barium (Ba) | 0.006 | 2.0 | 2.0 | - | - | 0.7 | |||||||
7. Antimony (Sb) | ND (<0.0004) | 0.01 | 0.006 | - | 0.005 | 0.02 | |||||||
8. Nickle (Ni) | ND (< 0.0003) | 0.02 | - | - | 0.02 | 0.07 | |||||||
9. Mercury (Hg) | ND (< 0.00004) | 0.001 | 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 (< 0.0004) | 0.1 | 1 | 0.04 | 0.1 | 3 | |||||||
Disinfection by-product | |||||||||||||
12.Trihalomethanes (THMs) | 0.00607 | 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)) | 0.0138 | 0.060 | 0.06 | 0.02 (MCAA) 0.03(DCAA) 0.03(TCAA) | - | 0.02(MCAA) 0.05(DCAA) 0.2(TCAA) | |||||||
14. Bromate | ND (<0.0007) | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | |||||||
15. Chlorite | ND (<0.02) | 0.7 | 1 | - | - | 0.7 | |||||||
Volatile Organics | |||||||||||||
16.Trichloroethylene | ND (<0.00045) | 0.005 | 0.005 | 0.01 | *10 | 0.02 | |||||||
17.Carbon Tetrachloride | ND (<0.00048) | 0.005 | 0.005 | 0.002 | - | 0.004 | |||||||
18.1,1,1-Trichloroethane | ND (<0.00048) | 0.20 | 0.20 | - | - | - | |||||||
19.1,2-Dichloroethane | ND (<0.00048) | 0.005 | 0.005 | - | 0.003 | 0.03 | |||||||
20.Vinyl chloride | ND (<0.0004) | 0.0003 | 0.002 | - | 0.0005 | 0.0003 | |||||||
21.Benzene | ND (<0.00047) | 0.005 | 0.005 | 0.01 | 0.001 | 0.01 | |||||||
22.Para-Dichlorlbenzene | ND (<0.00045) | 0.075 | 0.075 | - | - | 0.3 | |||||||
23.1,1-Dichloroethene | ND (<0.0005) | 0.007 | 0.007 | - | - | - | |||||||
24. Dichloromethane | ND (<0.00054) | 0.02 | 0.005 | 0.02 | - | 0.02 | |||||||
25. 1,2-Dichlorobenzene | ND (<0.00047) | 0.6 | 0.6 | - | - | 1 | |||||||
26. Toluene | ND (<0.00046) | 0.7 | 1 | - | - | 0.7 | |||||||
27. Xylenes | ND (<0.00068) | 0.5 | 10 | - | - | 0.5 | |||||||
28. cis-1,2-Dichloroethene | ND (<0.00048) | 0.07 | 0.07 | 0.04*9 | - | 0.05*9 | |||||||
29. trans-1,2-Dichloroethene | ND (<0.00044) | 0.1 | 0.1 | 0.04*9 | - | 0.05*9 | |||||||
30. Tetrachloroethene | ND (<0.00046) | 0.005 | 0.005 | 0.01 | *10 | 0.04 | |||||||
Pesiticides | |||||||||||||
31.Endosulfan | ND (<0.0000062) | 0.003 | - | 0.01 | *12 | - | |||||||
32.Lindane | ND (<0.000003) | 0.0002 | 0.0002 | - | *12 | 0.002 | |||||||
33.Butachlor | ND (<0.000062) | 0.02 | - | 0.03 | *12 | - | |||||||
34.2.4-Dichlorophenoxyacetic acid | ND (<0.000015) | 0.07 | 0.07 | 0.02 | *12 | 0.03 | |||||||
35.Paraquat*11 | ND (<0.00278) | 0.01 | - | 0.005 | *12 | - | |||||||
36.Methomyl | ND (<0.000195) | 0.01 | - | 0.03 | *12 | - | |||||||
37.Carbofuran | ND (<0.000185) | 0.02 | 0.04 | 0.005 | *12 | 0.007 | |||||||
38.Isoprocarb | ND (<0.000171) | 0.02 | - | 0.01 | *12 | - | |||||||
39.Methamidophos | ND (<0.000010) | 0.02 | - | - | *12 | - | |||||||
40.Diazinon | ND (<0.000023) | 0.005 | - | 0.003 | *12 | - | |||||||
41.Parathion | ND (<0.000066) | 0.02 | - | - | *12 | - | |||||||
42.EPN | ND (<0.000068) | 0.005 | - | 0.004 | *12 | - | |||||||
43.Monocrotoohos | ND (<0.000036) | 0.003 | - | - | *12 | - | |||||||
Persistent organic pollutants, POPs | |||||||||||||
44. Dioxin (pg WHO-TEQ/L) | 0.004 | 3 | 3 | 30*13 | - | - | |||||||
(B) Substances probably affecting health | |||||||||||||
1.Fluoride (F-) | 0.07 | 0.8 | 4.0*14 | 0.8 | 1.5 | 1.5 | |||||||
2.NO3-N (Nitrate Nitrogen ,As N) | 0.48 | 10.0 | 10.0 | 10 | 50 | 50 | |||||||
3.Silver (Ag) | ND (<0.0006) | 0.05 | 0.1*5 | - | - | - | |||||||
(C)Substances affecting palatability | |||||||||||||
1.Iron (Fe) | ND (<0.0014) | 0.3 | 0.3*5 | 0.3 | 0.2 | - | |||||||
2.Manganese (Mn) | ND (<0.0005) | 0.05 | 0.05*5 | 0.05 | 0.05 | - | |||||||
3.Copper (Cu) | ND (<0.0006) | 1.0 | 1.0*5 1.3*7 | 1.0 | 2.0 | 2.0 | |||||||
4.Zinc (Zn) | ND (<0.0007) | 5.0 | 5.0*5 | 1.0 | - | - | |||||||
5.Sulfate (SO4-2) | 11.0 | 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-) | 5.2 | 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 | 30.8 | 300 | - | 300 | - | - | |||||||
11.Total Dissolved Solids | 58 | 500 | 500*5 | 500 | - | - | |||||||
12. Aluminum (Total Al) | 0.059 | 0.2 | 0.05~0.2*5 | 0.2 | 0.2 | - | |||||||
D. Residual chlorine | 0.57 | 0.2~1.0 | 4 | - | - | 0.2-5.0 | |||||||
E. pH value | 7.2 | 6.0~8.5 | 6.5~8.5 *5 | 5.8~8.6 | 6.5~9.5 | - |
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 in Japan, and WHO set should not exceed 0.05 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 set the 2,3,7,8-TCDD(Dioxin) as 3x10-8 mg/L.
*14. USEPA also set the SMCL(Secondary Maximum Contaminant Limits)as 2 mg /L for fluoride Public acceptance of hardness varies considerably.
*15. The limt value of pesticide in Japan is the target for water quality management in 2019
*16. 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 in Japan, and WHO set should not exceed 0.05 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 set the 2,3,7,8-TCDD(Dioxin) as 3x10-8 mg/L.
*14. USEPA also set the SMCL(Secondary Maximum Contaminant Limits)as 2 mg /L for fluoride Public acceptance of hardness varies considerably.
*15. The limt value of pesticide in Japan is the target for water quality management in 2019
*16. 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.