Combined Sewerage System

A combined sewerage system is a type of sewer system that carries both stormwater and wastewater in a single pipe. The system is designed to handle both the dry weather flow of sewage from homes and businesses as well as the high flow rates that occur during rain events.

Types of Sewage

In a combined sewerage system, there are two types of sewage that flow through the system:

1. Sanitary Sewage: This refers to the wastewater that is generated from homes, businesses, and industries. It includes water from sinks, toilets, showers, washing machines, and other sources.

2. Storm Sewage: This refers to the rainwater and snowmelt that runs off streets, sidewalks, parking lots, and other surfaces during a rain event.

Function

The combined sewerage system works by capturing both the sanitary sewage and storm sewage in a single pipe. The combined sewage then flows to a treatment plant where it is treated before being discharged into a water body.

Advantages

- A combined sewerage system is cost-effective because it requires only one pipe to transport both types of sewage.
- It can reduce the amount of stormwater runoff that enters into the drainage system, which can reduce the risk of flooding.

Disadvantages

- During heavy rain events, the combined sewerage system can become overwhelmed, leading to sewage backups and overflows.
- The combined sewerage system can discharge untreated sewage into water bodies during extreme weather conditions.

Conclusion

In conclusion, a combined sewerage system carries both storm sewage and sanitary sewage. This system is designed to handle both types of sewage in a single pipe, which is cost-effective and can reduce the risk of flooding. However, during heavy rain events, the system can become overwhelmed, leading to sewage backups and overflows.