Licence conditions for pollution studies and reduction program


  

Licence conditions for pollution studies and reduction programs

Summary
 
Licence number: 2647
Title: Pollution Reduction Program 13 - Charmhaven STP Wet Weather Pond Remediation
Start date: 15 Oct 2021
 
Licence Condition
The Licensee must take any necessary actions (including the removal of accumulated sludge) to maximise the storage capacity of the CWWSP. The Licensee must safely maximise the storage capacity of the CWWSP by no later than 5pm Friday 29 January 2027.
Background
Deliverables
During the significant rainfall event of March 2021, the Charmhaven STP Wet Weather Storage Pond (CWWSP) overtopped due to the rate of inflow exceeding the capacity of the plant to store and pump to the outfall. The EPA note that the CWWSP has a dedicated spillway and the overtopping event resulted in a controlled discharge of treated effluent via the spillway to downstream waters and subsequently to Wallarah Creek. During reduction of the levels and operational monitoring in 2021, the licensee identified that over the course of the life of the pond, biosolids have accumulated at the base of the CWWSP which has created a reduction in depth and volume of capacity. The licensee is of the view that the removal of the accumulated biosolids will significantly increase the storage capacity for CWWSP during wet weather events. This, combined with ongoing effective pond and reticulation maintenance, will provide significant capacity to manage repeat occurrences of the significant inflows experienced during the 2021 rainfall event.
The Licensee must provide a report to the EPA on the actions taken to maximise the storage capacity of the CWWSP 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
The Licensee must provide to the EPA a full scope of works to maximise the storage capacity of the CWWSP (including the removal of accumulated sludge) 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