Source: WHO, 1996. Guidelines for drinking-water quality, 2nd ed. Vol. 2 Health criteria and other supporting information, p. 940-949; and WHO, 1998. Addendum to Vol. 2. p. 281-283. Geneva, World Health Organization. Summary tables. http://www.who.int/water_sanitation_health/GDWQ/Summary_tables/Sumtab.htm
Table A3.1. Bacteriological quality of all water intended for drinking
|
Organisms |
Guideline value |
|
E. coli or thermotolerant coliform bacteria |
Must not be detectable in any 100-ml sample |
Table A3.2. Inorganic constituents of health significance in drinking-water
|
|
Guideline value (mg/litre) |
Remarks |
|
Arsenic |
0.01 (P) |
For excess skin cancer risk of 6 × 10-4 |
|
Boron |
0.5 (P) |
|
|
Cadmium |
0.003 |
|
|
Chromium |
0.05 (P) |
|
|
Copper |
2 (P) |
Based on acute gastrointestinal effects |
|
Lead |
0.01 |
It is recognized that not all water will meet the guideline value immediately; meanwhile, all other recommended measures to reduce the total exposure to lead should be implemented |
|
Manganese |
0.5 (P) |
Substance at or below the health-based guideline value may affect the appearance, taste and odour of the water. |
|
Mercury (total) |
0.001 |
|
|
Molybdenum |
0.07 |
|
|
Nickel |
0.02 (P) |
|
|
Nitrate (as NO3-) |
50 (acute) |
|
|
Nitrite (as NO2-) |
3 (acute) 0.2 (P) (chronic) |
|
|
Selenium |
0.01 |
|
|
Uranium |
0.002 (P) |
|
(P) Provisional guideline value.
Table A3.3. Pesticides
|
|
Guideline value |
Remarks |
|
Alachlor |
20 |
For excess risk of 10-5 |
|
Aldicarb |
10 |
|
|
Aldrin/dieldrin |
0.03 |
|
|
Atrazine |
2 |
|
|
Bentazone |
300 |
|
|
Carbofuran |
7 |
|
|
Chlordane |
0.2 |
|
|
Chlorotoluron |
30 |
|
|
Cyanazine |
0.6 |
|
|
DDT |
2 |
|
|
1,2-dibromo-3-chloropropane |
1 |
For excess risk of 10-5 |
|
1,2-dibromoethane |
0.4-15 (P) |
For excess risk of 10-5 |
|
2,4-dichlorophenoxyacetic acid (2,4-D) |
30 |
|
|
1,2-dichloropropane (1,2-DCP) |
40 (P) |
|
|
1,3-dichloropropane |
|
NAD |
|
1,3-dichloropropene |
20 |
For excess risk of 10-5 |
|
Diquat |
10 (P) |
|
|
Heptachlor and heptachlor epoxide |
0.03 |
|
|
Hexachlorobenzene |
1 |
For excess risk of 10-5 |
|
Isoproturon |
9 |
|
|
Lindane |
2 |
|
|
MCPA |
2 |
|
|
Methoxychlor |
20 |
|
|
Metolachlor |
10 |
|
|
Molinate |
6 |
|
|
Pendimethalin |
20 |
|
|
Pentachlorophenol |
9 (P) |
For excess risk of 10-5 |
|
Permethrin |
20 |
|
|
Propanil |
20 |
|
|
Pyridate |
100 |
|
|
Simazine |
2 |
|
|
Terbuthylazine (TBA) |
7 |
|
|
Trifluralin |
20 |
|
|
2,4-DB |
90 |
|
|
Dichlorprop |
100 |
|
|
Fenoprop |
9 |
|
|
MCPB |
|
NAD |
|
Mecoprop |
10 |
|
|
2,4,5-T |
9 |
|
(P) Provisional guideline value.
Table A3.4. Substances and parameters in drinking-water that may give rise to complaints from consumers
|
|
Levels likely to give rise to consumer complaintsa |
Reasons for consumer complaints |
|
Physical parameters |
||
|
Colour |
15 TCUb |
appearance |
|
Taste and odour |
- |
should be acceptable |
|
Temperature |
- |
should be acceptable |
|
Turbidity |
5 NTUc |
appearance; for effective terminal disinfection, median turbidity = 1 NTU, single sample = 5 NTU |
|
Inorganic constituents |
||
|
|
Guideline value mg/litre |
Remarks |
|
Aluminium |
0.2 |
depositions, discoloration |
|
Ammonia |
1.5 |
odour and taste |
|
Chloride |
250 |
taste, corrosion |
|
Copper |
1 |
staining of laundry and sanitary ware (health-based provisional guideline value 2 mg/litre) |
|
Hardness |
- |
high hardness: scale deposition, scum formation low hardness: possible corrosion |
|
Hydrogen sulphide |
0.05 |
odour and taste |
|
Iron |
0.3 |
staining of laundry and sanitary ware |
|
Manganese |
0.1 |
staining of laundry and sanitary ware (health-based guideline value 0.5 mg/litre) |
|
Dissolved oxygen |
- |
indirect effects |
|
pH |
- |
low pH: corrosion high pH: taste, soapy feel preferably <8.0 for effective disinfection with chlorine |
|
Sodium |
200 |
taste |
|
Sulphate |
250 |
taste, corrosion |
|
TDS |
1 000 |
taste |
|
Zinc |
3 |
appearance, taste |
a The levels indicated are not precise numbers. Problems may occur at lower or higher values according to local circumstances. A range of taste and odour threshold concentrations is given for organic constituents.
b TCU, true colour unit.
c NTU, nephelometric turbidity unit.
