Inflow and outflow water quality from EWL and NWL
| . | COD . | BOD . | Suspended solids . | N-NH4 . | N-NO3 . | N-NO2 . | Inorganic nitrogen . | Total nitrogen . | Total phosphorus . |
|---|---|---|---|---|---|---|---|---|---|
| Average concentration in inlet (mg/l) | |||||||||
| EWL 2017 | 692 | 268 | 362 | 35.3 | 0.6 | 0.2 | 35.7 | 65.0 | 7.6 |
| EWL 2019 | 739 | 270 | 381 | 37.4 | 0.4 | 0.1 | 37.7 | 64.3 | 8.4 |
| NWL 2019 | 1,098 | 412 | 552 | 41.2 | 0.2 | 0.1 | 41.3 | 74.2 | 9.4 |
| Average concentration in outlet (mg/l) | |||||||||
| EWL 2017 | 34.8 | 6.2 | 9.2 | 9.4 | 8.0 | 1.6 | 18.9 | 21.9 | 0.7 |
| EWL 2019 | 32.4 | 5.5 | 7.0 | 4.9 | 8.8 | 0.1 | 13.9 | 16.0 | 1.0 |
| NWL 2019 | 24.6 | 2.1 | 6.5 | 0.3 | 6.5 | 0.0 | 6.7 | 8.1 | 0.7 |
| Average treatment efficiency | |||||||||
| EWL 2017 | 95% | 98% | 97% | 73% | x | x | 47% | 66% | 91% |
| EWL 2019 | 96% | 98% | 98% | 87% | x | x | 63% | 75% | 88% |
| NWL 2019 | 98% | 99% | 99% | 99% | x | x | 84% | 89% | 93% |
| Target values (mg/l or % where noted) | |||||||||
| NWL permit | 55 | 15 | 20 | x | x | x | x | 10 | 0.8 |
| EWL permit | 60 | 15 | 20 | 10 | x | x | x | 75% | 1.0 |
| 91/271/EEC | 125 | 25 | 35 | x | x | x | x | 10 (70–80%) | 1.0 |
| . | COD . | BOD . | Suspended solids . | N-NH4 . | N-NO3 . | N-NO2 . | Inorganic nitrogen . | Total nitrogen . | Total phosphorus . |
|---|---|---|---|---|---|---|---|---|---|
| Average concentration in inlet (mg/l) | |||||||||
| EWL 2017 | 692 | 268 | 362 | 35.3 | 0.6 | 0.2 | 35.7 | 65.0 | 7.6 |
| EWL 2019 | 739 | 270 | 381 | 37.4 | 0.4 | 0.1 | 37.7 | 64.3 | 8.4 |
| NWL 2019 | 1,098 | 412 | 552 | 41.2 | 0.2 | 0.1 | 41.3 | 74.2 | 9.4 |
| Average concentration in outlet (mg/l) | |||||||||
| EWL 2017 | 34.8 | 6.2 | 9.2 | 9.4 | 8.0 | 1.6 | 18.9 | 21.9 | 0.7 |
| EWL 2019 | 32.4 | 5.5 | 7.0 | 4.9 | 8.8 | 0.1 | 13.9 | 16.0 | 1.0 |
| NWL 2019 | 24.6 | 2.1 | 6.5 | 0.3 | 6.5 | 0.0 | 6.7 | 8.1 | 0.7 |
| Average treatment efficiency | |||||||||
| EWL 2017 | 95% | 98% | 97% | 73% | x | x | 47% | 66% | 91% |
| EWL 2019 | 96% | 98% | 98% | 87% | x | x | 63% | 75% | 88% |
| NWL 2019 | 98% | 99% | 99% | 99% | x | x | 84% | 89% | 93% |
| Target values (mg/l or % where noted) | |||||||||
| NWL permit | 55 | 15 | 20 | x | x | x | x | 10 | 0.8 |
| EWL permit | 60 | 15 | 20 | 10 | x | x | x | 75% | 1.0 |
| 91/271/EEC | 125 | 25 | 35 | x | x | x | x | 10 (70–80%) | 1.0 |