Sri Lankan sets ambient water quality standards 
The government of Sri Lanka promulgated the National Environmental (Ambient Water Quality) Regulations, No. 01 of 2019 on November 5, 2019. No pollutant shall be discharged into inland surface water in excess of the ambient water quality standards specified in the Schedule to the regulations. The ambient water quality standards specify discharge limits for pollutants for each of the following six water quality categories.
Category A: Water that requires simple treatment (simple filtration and boiling at 100 degrees Celsius) for drinking
Category B: Bathing and recreational water
Category C: Water suitable for aquatic life
Category D: Water source that requires general treatment process for drinking
Category E: Water suitable for irrigation and agricultural activities
Category F: Water with minimum quality that does not fall into categories A to E
Schedule: Ambient water quality standards (excerpt)
|
No. |
Parameter | Unit | A | B | C | D | E |
F |
|
| General |
4 |
TSS | mg/l, max | 25 | – | 40 | 1,500 | 2,100 |
– |
| Nutrient |
10 |
NO3 -N | mg/l, max | 10 | 10 | 10 | 10 | – |
10 |
| Other |
13 |
Chloride (CI) | mg/l, max | 250 | – | – | 250 | 600 |
– |
| Metal |
17 |
Cd, total | µg/l, max | 5 | – | 5 | 5 | – |
5 |
|
23 |
Hg, total | 1 | 1 | 1 | 1 | 2 |
2 |
||
|
26 |
Zn, total | 1,000 | – | 1,000 | 1,000 | 2,000 |
24,000 |
||
|
28 |
As, total | 50 | 50 | 50 | 50 | 50 |
50 |
||
| Organic Micro Pollutant |
30 |
Phenolic compounds | µg/l, max | 2 | 5 | 2 | 5 | 5 |
5 |
| Micro Organism |
35 |
Total Coliform | MPN/100ml, max | 10,000 | 10,000 | – | 10,000 | – |
– |
The National Environmental (Ambient Water Quality) Regulations, No. 01 of 2019 can be downloaded from the following URL.
http://www.cea.lk/web/images/pdf/epc/2148-20_E-1.pdf
