Contaminated surface or groundwater discharge to sewer
The flow of surface water and/or ground water to the sewerage system can cause severe operational difficulties and potentially increase the number of sewer overflows. For these reasons surface water and ground water discharge are generally considered a 'prohibited discharge' to the sewerage system.
We recognise that there are some exceptional circumstances where it is environmentally beneficial to accept surface or groundwater to sewer under strict controls. We do not automatically allow surface water and/or ground water discharge to the sewerage system.
This is only considered where:
- Other options for discharge have been investigated and denied (e.g. to stormwater, ocean or lake). Formal evidence of denial notification may be required); and
- our review confirms that the proposed discharge will not adversely impact the operation of the sewerage system and treatment process; and
- the discharge is for short term only.
How to apply for a trade waste deed
If the development does not already incorporate an approved trade waste pre-treatment facility for the operations onsite, a technical assessment application needs to be submitted to us for recognition of the proposed trade waste pre-treatment facility installation to comply with our requirements.
The application process
- Make an initial enquiry
You need to submit details of the proposed groundwater discharge so we can determine the load of contaminants being discharged to the sewerage system and whether it meets our requirements. Contact our team and we will review your request.
- Submit a Hydraulic Assessment application
If the initial enquiry is approved a hydraulic assessment application will be required. You will need to include details of proposed discharge configuration including a site plan, pre-treatment system/s, pump locations, pump flow rates, 'magflow' meter size, location and start read, and discharge to sewer location and configuration. Learn more about the hydraulic design assessment process.
- Submit a Trade Wastewater Deed application
You will need to include a completed application form, the proposed dewatering regime, pump rate, time of operation, total volume to be discharged, full analysis of chemical, biological, and physical characteristics of the ground water source (e.g. concentrations, test pit locations, distribution across site) and information on how the applicant proposes to meet the allowable discharge concentrations nominated elsewhere in this standard.
Thirsty for more advice?
If you need more advice on contaminated surface or groundwater discharge to sewer get your questions answered by contacting our team.