10 Difference Between Combined and Separate Sewer System
Following are the 10 difference or comparison between combined and separated sewer system:
| Combined Sewer System | SL NO | Separate Sewer System |
| In this system, only one set of the sewer is laid and carries both sewage and stormwater. | 1 | In this system, two sets of sewers are laid for carrying sewage and stormwater separately. |
| The cleaning of sewers is easy as they are of large in size. | 2 | The cleaning of sewers is difficult as they are of small in size. |
| The maintenance cost is less. | 3 | The maintenance cost is high. |
| The load on the treatment plant becomes high. | 4 | The load on the treatment plant is less. |
| Self-cleaning velocity is easily achieved. | 5 | The self-cleaning velocity is not easily achieved. |
| Strength of sewage is less. | 6 | Strength of sewage is more. |
| This system proves to be uneconomical when pumping is required for the lifting of sewage. | 7 | This system proves to be economical when pumping is required for the lifting of sewage. |
| The stormwater is unnecessarily polluted. | 8 | The stormwater is not unnecessarily polluted. |
| The initial cost is less. | 9 | The initial cost is more as compared to the combined sewer system. |
| This system is suitable when the rainfall is small and evenly spread throughout the year. | 10 | This system is suitable when the rainfall is uneven or it is heavy for a short duration. |
Read More:
Choice of The Separate Sewer System
Partially Separate Sewer System And Their Advantages & Disadvantages