Managing groundwater
Learn about the requirements for releasing groundwater to the sewer during construction.
Groundwater is water under the land surface.
You can find our Groundwater Policy outlined in your trade waste agreement.
The policy is there to ensure:
- groundwater flows are managed under our guiding operational principles
- hydraulic loads in the receiving sewer are maintained
- excessive flow-rates are avoided.
Groundwater and construction
If you think you will come across groundwater during excavation, you’ll need to provide sample results with your trade waste application, outlined in the table below.
Groundwater can only be discharged to the sewer during construction. We will not accept groundwater on a permanent basis after construction is complete.
Customers must follow the conditions of their agreement including:
- installing and maintaining treatment processes
- sampling the waste stream
- performing calibrations
- paying trade waste charges
- any other requirements we deem appropriate for the site.
Connection to the sewer
If the construction site doesn’t have an existing connection to the sewer, you will need to apply for one by contacting our connections department by calling 1300 299 228.
The table below outlines our requirements for a sewer connection.
| Type of discharge | Sample data (pre-discharge) | Treatment (minimum requirement) | Flow measurement | Maximum flow rate |
|---|---|---|---|---|
|
Groundwater OR Groundwater combined with stormwater |
Scans: VOC, Metals, SAR Metals, Phenols and Cresols, PAHs, BTEX, TRH/TPH, Aromatic Hydrocarbons and PFAS Parameters: Suspended Solids, TDS/iTDS, TKN, TN, BOD, Sulphide, Ammonia and TOS |
Suitably sized sedimentation tank Additional treatment may be required depending on your ability to meet our Trade waste acceptance criteria |
Electromagnetic flow meter | 2.0 litres per second |
| Stormwater |
You are not required to maintain a sampling program We may request a sample from time-to-time for auditing purposes |
Suitably sized sedimentation tank |
Electromagnetic flow meter or agreed volume (based on estimated rainfall and surface area of the site) For more information visit our page on Managing stormwater. |
Options for groundwater disposal after construction
| Options | Method |
|---|---|
| Prevention | Construct a sealed basement that prevents groundwater seepage and removes the need for disposal. |
| Reuse on-site | Diversion of groundwater to a fit-for-purpose reuse opportunity. For example, toilet flushing. |
| Off-site disposal | Capturing groundwater seepage in a holding tank (or similar) and having it removed off site by a third-party waste treater. |
Contact us
Email trade.waste@gww.com.au or call 13 44 99.
