A vacuum sewer system consists of the following components:
- A vacuum station
- a vacuum pump located inside the vacuum station
- a collection chamber inside the vacuum station
- and a vacuum pipeline system
How it works
Wastewater is moved from the source, usually a wastewater collection sump attached to each house, to the collection chamber at the vaccuum station. When the collected wastewater in the sump reaches a specified height, a valve opens and the wastewater is transported by a stream of air to a central vacuum station.
The vacuum sewer pipe system is designed to incorporate low and high points. When the wastewater accumulates in the low points, a stream of high pressure air pushes the wastewater out of the low point and over subsequnet high points to its penultimate destination in the vacuum station, whence it is transported to the wasterwater treatment plant.
Vacuum pumps maintain the vacuum in the collection tank and in the sewer pipe system.
House connection system design diagram
Image courtesy AirVac
Use Cases
The following are examples of factors that may result in a vacuum sewer may be a superior option to a conventional gravity sewer system:
- Soil instability
- high water table
- undulating terrain
- rock
- flat terrain
- sensitive ecosystem
- urban development in rural areas
Advantages
- Manholes not required
- Pipes can be installed at shallower depth
- Smaller diameter pipes
- Higher scouring velocities break down solids and reduce odour generation
- Elimination of infiltration
Disadvantages
- Mechanical valves installed at each property, thereby potentially increasing maintenance requirements
- Vacuum stations are larger than conventional pump stations, which makes them more costly to install
- Difficult to fault-find. It can take longer to determine the location of a problem.
- Requires electrical power to operate the collection pump system
- Requires regular maintenance on pump and transmission system
- Many utilities have had little experience with such systems
Places that operate a vacuum sewer system
Related Pages
Contributors
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External Links and References
- WSA 06-2008 Vacuum Sewerage Code V1.2
- Vacuum Sewers - Access Engineering Library
- Vacuum Sewers 101 - Airvac
- Penneshaw CWMS Collection Network Options Assessment - Comparative Analysis of Gravity, Pressure and Vacuum Systems
- Vacuum Sewerage System Fact Sheet - Eurobodalla Shire Council
- The Feasibility of Vacuum Sewer Implementation In Venice, Italy
- Feasibility of Vacuum Sewer Implementation In Venice, Italy - PowerPoint Presentation
- Vacuum Sewer System on Palm Jumeirag in Dubai
- Vacuum Sewers Implementation Tools
- Google Search