Table 9: Maximum permissible limits for industrial effluent discharges (in mg/litre)
Parameter
|
Into inland surface waters
Indian standards: 2490(1974) |
Into public sewers
Indian Standards:3306(1974) |
On land for irrigation
Indian Standards: 3307 (1974) |
pH |
5.50-9.00
|
5.50-9.00
|
5.50-9.00
|
Biological oxygen demand (for 5 days at 20°C) |
30.00
|
350.00
|
100.00
|
Chemicals oxygen demand |
250.00
|
--
|
--
|
Suspended solids |
100.00
|
600.00
|
200.00
|
Total dissolved solids (inorganic) |
2100.00 0
|
2100.00
|
2100.0
|
Temperature (°C) |
40.00
|
45.00
|
--
|
Oil and grease |
10.00
|
20.00
|
10.00
|
Phenolic compounds |
1.00
|
5.00
|
--
|
Cyanides |
0.20
|
2.00
|
0.20
|
Sulphides |
2.00
|
--
|
--
|
Fluorides |
2.00
|
15.00
|
--
|
Total residual chlorine |
1.00
|
--
|
--
|
Pesticides |
--
|
--
|
--
|
Arsenic |
0.20
|
0.20
|
0.20
|
Cadmium |
2.00
|
1.00
|
--
|
Chromium (hexavalent) |
0.10
|
2.00
|
--
|
Copper |
3.00
|
3.00
|
--
|
Lead |
0.10
|
1.00
|
--
|
Mercury |
0.01
|
0.01
|
--
|
Nickel |
3.00
|
3.00
|
--
|
Zinc |
5.00
|
15.00
|
--
|
Chlorides |
1000.00
|
1000.00
|
600.00
|
Boron |
2.00
|
2.00
|
2.00
|
Sulphates |
1000.00
|
1000.00
|
1000.00
|
Sodium(%) |
--
|
60.00
|
60.00
|
Ammonical nitrogen |
50.00
|
50.00
|
--
|
Radioactive materials |
.
|
.
|
.
|
Alpha emitters (milli curie/millilitre) |
10-7
|
10-7
|
10-8
|
Beta emitters (as curie/millilitre) |
10-6
|
10-6
|
10-7
|