Licence conditions for pollution studies and reduction program


Licence conditions for pollution studies and reduction programs

Licence number: 2647
Title: Pollution Reduction Program 6 - Wyong South STP Wet Weather Pond Works Schedule
Start date: 30 Jul 2021
Licence Condition
Background Central Coast Council (CCC) has notified the EPA that during two rainfall events in 2020 and 2021 the Wyong South STP Wet Weather Storage Pond (WSWWSP) has overtopped causing concerns with the structural integrity of the pond wall. The EPA note that 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 then to Ourimbah Creek. During both of these events CCC implemented emergency pumping to Ourimbah Creek to reduce levels in the WSWWSP. In response to these events the EPA requested that the licensee engage a suitably qualified person to prepare a report on the structural integrity of the WSWWSP wall and make any necessary recommendations based on the geotechnical assessment. On 8 April 2021 CCC provided the report titled "Central Coast Council (NSW), Wyong STP Wet Weather Storage Pond Embankment Geotechnical Investigation Report, July 2020, GHD (the report). The report identified risks with the structural integrity of the pond wall due to potential slope stability, erosion and dispersive soils and potential risks under a rapid draw-down situation. The report recommended remedial options to address the identified issues at Section 7.5 of the report and also made a number of recommendations for further investigations, assessment, instrumentation and monitoring at Section 7.6 of the report. The EPA is not aware if any of the recommendations made in the report have been actioned or completed. Deliverables The licensee must provide an Action Report to the EPA detailing all of the actions and recommendations made in the report that have been completed to date. The Action Report must also provide a full scope of works including commencement and completion dates for all outstanding works identified by CCC to address the issues identified in the report. It is the EPA's intention to formalise all outstanding works and/or studies identified by the licensee and any further investigations and reports into this issue made by a suitably qualified professional as a Pollution Reduction Program on this licence. The report must be provided to the EPA's Director - Metropolitan North by no later than Friday 26 November 2021 at