Gravity sewer systems
A gravity sewer connection or disconnection application may be submitted by the property owner, or a person that has authority to act on behalf of the property owner (e.g. plumber, builder, managing agent).
Location of the sewer main
Where practical, we provide an individual gravity sewer connection point to each separate lot. This sewer connection point is normally located within the boundaries of the lot and sized 150mm.
For gravity sewer connections the sewer main will be:
- Within the property
The sewer point of connection is the arm of the junction located in our sewer main within the customer’s property. The junction is sealed at the time of construction. We own the junction and adjacent sewer main; or - Outside of property
The sewer point of connection is located at the end of a branch/sideline from the sewer main terminating within the customer's property.
We may specify a 'Y-junction' at the end of the sideline to which the property connection is to be made to the branch of the junction. This is to allow future maintenance or possible extension from the straight line section of the junction. We own the branch/sideline and 'Y-junction'.
Resources
Connecting to a gravity sewer system
Follow our three step process to connect a gravity sewer system.
What you need to know
If the property owner, builder or managing agent is to make the application to connect, it is your responsibility to ensure all applications have been submitted and inspections booked prior to any physical water connection works.
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Step 1: Application for services connection
To complete the application, you will need the following information:
- Your licence number, name and contact details.
- Book inspection dates for the connection works.
This process must take place no more than two weeks prior and a minimum two days prior to making the physical connection to sewer.
At the application stage you will be notified of any special considerations applicable for the sewer connection/s. Examples include sewer connection type and sewer point of connection location.
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Step 2: Connect to the sewer system
You must determine the type of sewer connection applicable for the development - boundary trap or inspection shaft. View Drawing TSS 006 Sewer Connection Boundary Trap Sewer Shaft or (Residential) or Drawing TSS 005 Sewer Connection Non-Boundary Trap (Residential)
Boundary trap connections are generally required for:
- Connections to sewerage mains that are greater than or equal to 300mm
- Properties connected to a sewer main directly affected by a pumping or rising main, shall incorporate a boundary trap and a minimum of 100mm in-duct vent
- Historical boundary trap areas
- Where it is a trade waste requirement to discharge to sewer via a boundary trap
- Where a hydraulic assessment review has directed the installation of a boundary trap
Note: When replacing a sewer shaft in a boundary trap area the sewer shaft must consist of an approved boundary trap and induct vent. The inspection opening immediately downstream of the boundary trap is recommended to be extended to finished surface level and terminated with an air tight removable lid for maintenance purposes.
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Step 3: Inspection of the sewer connection
We do not regulate sanitary drainage systems. Contact Building Commission NSW for all sewer connection inspections.
Disconnecting from a gravity sewer system
Where a property’s sewer service has become redundant, or is not to be redeveloped and becomes disused, it can be disconnected from our sewer system. Disused sewer services are to be sealed off at the point of connection using approved materials in the accordance with AS/NZS3500.2 Plumbing and Drainage and our requirements.
Follow our three step process to disconnect a gravity sewer system.
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Step 1: Submit an application
To complete the application, you will need:
- Your licence number, name and contact details.
- To book inspection dates for the connection works.
This process must take place no more than two weeks prior and a minimum two days prior to making the physical disconnection of sewer.
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Step 2: Disconnect the sewer service
Disconnection incorporates installing a 150mm UPVC socket and screwed cap at the point of connection in an approved manner which maintains the integrity of the sewer main. This configuration allows connection for future development of the property by removing the screwed UPVC cap.
Criteria for the sewer point of connection have changed over time. Existing points of connection may be at depths greater than current accepted depths. Under these circumstances it remains the property owner’s responsibility to seal off the disused sewer service at the point of connection irrespective of the depth. Sealing a sewer service at the inspection shaft is not allowed.
We require a mandatory disconnection inspection with appropriate fees paid.
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Step 3: Inspection of the disconnection
We conduct random inspections of sewer disconnections to ensure compliance with our standards. It is your responsibility to ensure all works comply our Wastewater Connection Standard and the Plumbing Code of Australia.
Sewer soffit requirements
The soffit is the highest point of the internal surface of a pipe. There are minimum measurements between the soffit of the sewer main and the spill level of the overflow relief gully (ORG).