Environmental Issues
Public registers
POEO Public Register
Licences, applications and notices search
Penalty notices search
Enforceable undertakings search
Enforceable undertakings media releases
Exemptions and approvals search
Prosecutions or civil proceedings search
Terms of use: POEO public register
Licensing FAQs
List of licences
Unlicensed premises regulated by the EPA
Contaminated land record of notices
About the record of notices
List of notified sites
Tips for searching
Disclaimer
Dangerous goods licences
Pesticide licences
Radiation licences
Home
Public registers
POEO Public Register
Licences, applications and notices search
Licence conditions for pollution studies and reduction program
Licence conditions for pollution studies and reduction programs
Summary
Licence number:
2647
Title:
Pollution Reduction Program 12 - Wyong South STP Wet Weather Pond Remediation
Start date:
16 Oct 2021
Licence Condition
The Licensee must take any necessary actions to safely maximise storage capacity (including the removal of accumulated sludge) and safely deal with high volume inflows and outflows at the WSWWSP. The Licensee must safely maximise the storage capacity (including the removal of accumulated sludge) and safely deal with high volume inflows and outflows at the WSWWSP by no later than Friday 29 January 2027.
During the significant rainfall events of 2020 and 2021, the Wyong South Wet Weather Storage Pond (WSWWSP) overtopped due to the rate of inflow exceeding the capacity of the plant to store and pump to the outfall. The WSWWSP has no dedicated spillway, and the overtopping events resulted in uncontrolled discharges of treated effluent over the pond wall to downstream waters and subsequently to Ourimbah Creek. At the time of the discharges, the licensee notified the EPA of concerns regarding the structural integrity of the WSWWSP wall and in order to mitigate risk of failure, implemented emergency pumping to Ourimbah Creek to reduce levels in the WSWWSP and subsequently reduce the risk of wall failure. The licensee subsequently engaged an external consultant to investigate structural wall integrity and recommend mitigative actions. During implementation of the actions from that report, the licensee has identified that over the course of the life of the pond, biosolids have accumulated at the base of the WSWWSP which has created a reduction in depth and volume of capacity. The licensee proposes that removal of the accumulated biosolids will significantly increase the storage capacity for WSWWSP during wet weather events. This, combined with ongoing effective pond and reticulation maintenance, will provide increased capacity to manage repeat occurrences of the significant inflows experienced during the 2020 and 2021 rainfall events. However, even with this increased capacity, modelling by the licensee has suggested other pond modifications may also be necessary.
The Licensee must provide to the EPA a full scope of works to safely maximise storage capacity (including the removal of accumulated sludge) and safely deal with high volume inflows and outflows at the WSWWSP by 5pm Friday 3 October 2025. The scope of works must include evidence that the Licensee can feasibly complete the works by Friday 29 January 2027. The scope of works must be provided in writing to: info@epa.nsw.gov.au
The Licensee must provide a report to the EPA on the actions taken to safely maximise storage capacity and safely deal with high volume inflows and outflows at the WSWWSP at least every 6 months until all relevant works are completed (nominally being the first Friday in April and October). The first report must be provided to the EPA before 5pm Friday 4 October 2024. The report must be provided in writing to: info@epa.nsw.gov.au
Background
Deliverables