| |
Essential Characteristic |
| 1. |
Colour Hazen
Units, Max |
5 |
Above 5, consumer acceptance decreases |
25 |
Extended to 25 only if toxic
Substance are not suspect in absence of alternate
sources |
| 2. |
Odour |
Unobjectionable |
- |
- |
a) test
cold and when heated
b) test
are several dilutions |
| 3. |
Taste |
Agreeable |
- |
- |
Test to be conducted only after safely has been established
|
| 4. |
Turbidity (NTU) Max |
5 |
Above 5, consumer acceptance decreases |
10 |
- |
| 5. |
pH value |
6.5 to 8.5 |
Beyond this range the water will after the mucous
membrane and/or water supply system
|
No relaxation |
- |
| 6. |
Total
Hardness
(mg/L)
CaCO3 |
300 |
Encrustation in water supply structure and adverse
effects on domestic use |
600 |
- |
| 7. |
Iron (mg/L
Fe) Max |
0.3 |
Beyond this limit taste/appearance are affected;
has adverse effects on domestic uses and
water supply structure and promotes iron
bacteria |
1.0 |
- |
| 8. |
Chlorides
250
(mg/L,
Cl) Max |
250 |
Beyond
effects outside the desirable limit |
1000 |
- |
| 9. |
Residual
free
Chlorine
(mg/L), Max |
0.2 |
- |
- |
To
be applicable only when water is chlorinated.
Tested at customer end. When protection
against viral infection is required, it
should be min. 0.5 mg/L. |
| |
Desirable Characteristics |
| 10. |
Dissolved
solids mg/L. Max |
500 |
Beyond
this, palatability decreases and may cause
gastrointestinal irritation. |
2000 |
- |
| 11. |
Calcium
(mg/L, Ca) Max. |
75 |
Encrustation
in water supply structure and adverse effects
on domestic use. |
200 |
- |
| 12. |
Magnesium
(mg/L, Mg) Max |
30 |
Encrustation
in water supply structure and adverse effects
on domestic use. |
100 |
- |
| 13. |
Copper
(mg/L, Cu) Max |
0.05 |
Astringent
taste dis – coloration and corrosion of
pipes fittings and utensils will be caused
beyond this. |
1.5 |
- |
| 14. |
Manganese
(mg/L,
Mn) Max |
0.1 |
Beyond
this limit taste/appearance are affected,
has advers effect on domestic use and water supply structure
|
0.3 |
- |
| 15. |
Sulphate
(mg/L,
SO4) Max. |
200 |
Beyond
this causes gastro intestinal irritation
when magnesium or sodium are present |
400 |
May
be extended upto 400 provided magnesium
(as Mg) does not exceed 30 |
| 16. |
Nitrate
(mg/L, NO3) Max. |
45
|
Beyond
this methaemo – globinemia takes place.
|
100 |
- |
| 17. |
Fluoride
(mg/L, F) Max. |
1.0 |
Fluoride
may be kept as low as possible. High fluoride
may cause fluorosis. |
1.5 |
- |
| 18. |
Phenolic
Compounds
(mg/L C6H5OH) Max. |
0.001 |
Beyond
this, it may cause objectionable taste and
odour |
0.002 |
- |
| 19. |
Mercury
(mg/L Hg) Max |
0.001 |
Beyond
this the water becomes toxic |
No
Relaxation. |
To
be tested when pollution is suspected |
| 20 |
Cadmium
(mg/L,
Cd) Max |
0.01 |
Beyond
this the water becomes toxic |
No
Relaxation. |
To
be tested when pollution is suspected |
| 21. |
Selenium
(mg/L,
Se) Max |
0.01 |
Beyond
this the water becomes toxic. |
No
Relaxation. |
To
be tested when pollution is suspected |
| 22. |
Arsenic
(mg/L,
As) Max. |
0.05 |
Beyond
this the water becomes toxic |
No
Relaxation |
To
be tested when pollution is suspected |
| 23. |
Cyanide
|
0.05 |
Beyond
this the water becomes toxic |
No
Relaxation |
To
be tested when pollution is suspected |
| 24. |
Lead
(mg/L Pb) Max. |
0.05 |
Beyond
this the water becomes toxic |
No
Relaxation |
To
be tested when pollution is suspected |
| 25. |
Zinc
(mg/L, Zn) Max. |
5 |
Beyond
this limit it can cause astringent taste
and an opalescence in water |
15 |
To
be tested when pollution is suspected |
| 26. |
Anionic
detergents (mg/L, MBAS) Max |
0.2 |
Beyond
this limit it can cause a light froth in
water |
1.0 |
To
be tested when pollution is suspected |
| 27. |
Chromium
(mg/L,
Cr6+
|
0.05 |
May
be carcinogenic above this limit |
- |
- |
| 28. |
Polynuclear
Aromatic
Hydrocarbons
(mg/l,
PAH) Max
|
- |
May
be carcinogenic |
- |
- |
| 29. |
Mineral
oil
(mg/L)
|
0.01 |
Beyond
this limit, undesirable taste and odour after
chlorination takes place |
0.03 |
To
be tested when pollution is suspected |
| 30. |
Pesticides
(mg/L) max |
Absent |
Toxic |
