The Central Pollution Control Board (CPCB) has developed a concept of designated best use by classifying water resources of the country according to their uses for setting water quality objectives for different water bodies. According to this, out of the several uses of water of a particular body, the use which demands highest quality is termed its designated best use. Five designated best uses have been identified. This classification helps the water quality managers and planners to set water quality targets and design suitable restoration programs for various water bodies.
|
WATER QUALITY CRITERIA & DESIGNATED BEST USES |
||
|
Designated Best Use |
Class |
Criteria |
|
Drinking Water Source without conventional
treatment but after disinfection |
A |
1.Total Coliforms Organism, MPN/100ml shall be 50
or less 2. pH between 6.5 and 8.5 3. Dissolved Oxygen, 6mg/l or more 4. Biochemical Oxygen Demand 5 days 20 °C, 2mg/l or less |
|
Outdoor bathing (Organised) |
B |
1.Total Coliforms Organism MPN/100ml shall be 500
or less 2. pH between 6.5 and 8.5 3. Dissolved Oxygen 5mg/l or more 4. Biochemical Oxygen Demand 5 days 20 °C, 3mg/l or less |
|
Drinking water source after conventional treatment
and disinfection |
C |
1. Total Coliforms Organism MPN/100ml shall be
5000 or less 2. pH between 6 and 9 3. Dissolved Oxygen 4mg/l or more 4. Biochemical Oxygen Demand 5 days 20 °C, 3mg/l or less |
|
Propagation of Wild life and Fisheries |
D |
1. pH between 6.5 and 8.5 2. Dissolved Oxygen 4mg/l or more 3. Free Ammonia (as N) 4. Biochemical Oxygen Demand 5 days 20 °C, 2mg/l or less |
|
Irrigation, Industrial Cooling, Controlled Waste
disposal |
E |
1. pH between 6.0 and 8.5 2. Electrical Conductivity at 25 °C micro mhos/cm, maximum 2250 3. Sodium absorption Ratio Max. 26 4. Boron Max. 2mg/l |
|
|
Below-E |
Not meeting any of the A, B, C, D & E criteria |
|
Source: CPCB |
||
