Drinking Water specification
|
S. No. |
Substance or Characteristic |
Requirement (Desirable limit) |
Undesirable Effect Outside the Desirable Limit |
Permissible Limit in the Absence of Alternate Source |
|
Essential Characteristics |
||||
|
i) |
Colour, Hazen units Max. |
5 |
Above 5, Consumer acceptance decreases |
25 |
|
ii) |
Odour |
Unobjectionable |
- |
- |
|
iii) |
Taste |
Agreeable |
- |
- |
|
iv) |
Turbidity, NTU, Max. |
5 |
Above 5, consumer acceptance decrease |
10 |
|
v) |
pH Value |
6.5 to 8.5 |
Beyond this range the water will effect the mucous membrane and/ or water supply system |
No relaxation |
|
vi) |
Total hardness (as CaCO3) mg/L, Max. |
300 |
Encrustation in water supply structure and adverse effects on domestic use |
600 |
|
vii) |
Iron (as Fe) mg/L, Max. |
0.3 |
Beyond this limit taste/appearance are affected, has adverse effect on domestic uses and water supply structures, and promotes iron bacteria |
1.0 |
|
viii) |
Chlorides (as Cl) mg/L, Max. |
250 |
Beyond this limit taste, corrosion and palatability are affected |
1000 |
|
ix) |
Residual, free chlorine mg/L, Min. |
0.2 |
- |
- |
|
Desirable Characteristics |
||||
|
x) |
Dissolved solids mg/L, Max. |
500 |
Beyond this palatability decreases and may cause gastro intestinal irritation |
2000 |
|
xi) |
Calcium (as Ca) mg/L, Max. |
75 |
Encrustation in water supply structure and adverse effects on domestic use |
200 |
|
xii) |
Copper (as Cu) mg/L, Max. |
0.05 |
Astringent taste, discoloration and corrosion of pipes, fitting and utensils will be caused beyond this |
1.5 |
|
xiii) |
Manganese (as Mn) mg/L, Max. |
0.1 |
Beyond this limit taste/appearance are affected, has adverse effect on domestic uses and water supply structures |
0.3 |
|
xiv) |
Sulphate (as SO4) mg/L, Max. |
200 |
Beyond this cause gastro intestinal irritation when magnesium or sodium are present |
400 |
|
xv) |
Nitrate (as NO3) mg/L, Max. |
45 |
Beyond this methaemoglobinemia takes place |
100 |
|
xvi) |
Fluoride (as F) mg/L, Max. |
1.0 |
Fluoride may be kept as low as possible. High fluoride may cause fluorosis |
1.5 |
|
xvii) |
Phenolic compounds (as C6 H5 OH) mg/L, Max. |
0.001 |
Beyond this, it may cause objectionable taste and odour |
0.002 |
|
xviii) |
Mercury (as Hg) mg/L, Max. |
0.001 |
Beyond this the water becomes toxic |
No relaxation |
|
xix) |
Cadmium (as Cd) mg/L, Max. |
0.01 |
Beyond this the water becomes toxic |
No relaxation |
|
xx) |
Selenium (as Se) mg/L, Max. |
0.01 |
Beyond this the water becomes toxic |
No relaxation |
|
xxi) |
Arsenic (as As) mg/L, Max. |
0.05 |
Beyond this, the water becomes toxic |
No relaxation |
|
xxii |
Cyanide (as CN) mg/L, Max. |
0.05 |
Beyond this limit, the water becomes toxic |
No relaxation |
|
xxiii |
Lead (as Pb) mg/L, Max. |
0.05 |
Beyond this limit the water becomes toxic |
No relaxation |
|
xxiv |
Zinc (as Zn) mg/L, Max. |
0.5 |
Beyond this limit it can cause as stringent taste and an opalescence in water |
1.5 |
|
xxvi |
Anionic detergent (as MBAS) mg/L, Max. |
0.2 |
Beyond this limit it can cause a light froth in water |
1.0 |
|
xxvii |
Chromium (as Cr+) mg/L, Max. |
0.05 |
May be carcinogenic above this limit |
No relaxation |
|
xxvii |
Poly nuclear aromatic hydrocarbons (as PAH) g/L, Max. |
- |
May be carcinogenic |
- |
|
xxviii |
Mineral Oil mg/L, Max. |
0.01 |
Beyond this limit undesirable taste and odour after chlorination take place |
0.03 |
|
xxix) |
Pesticides mg/L, Max. |
Absent |
Toxic |
0.001 |
|
xxx) |
Radioactive materials a) Alpha emitters Bq/L, Max. |
-
|
-
|
0.1 |
|
|
b) Beta emitters pei/L, Max. |
- |
- |
- |
|
xxxi) |
Alkalinity mg/L, Max. |
200 |
Beyond this limit taste becomes unpleasant |
600 |
|
xxxii) |
Aluminum (as Al) mg/L, Max. |
0.03
|
Cumulative effect is reported to cause dementia |
0.2 |
|
xxxiii) |
Boron mg/L, Max. |
1 |
- |
5 |