Licence conditions for pollution studies and reduction program


  

Licence conditions for pollution studies and reduction programs

Summary
 
Licence number: 21229
Title: Clean Water Diversion Works - Emplacement Cell & Water Storage Lining - Discharge Concentration and Discharge Volume Limits
Start date: 13 Jun 2024
 
Licence Condition
By 22 November 2024, the licensee must complete and submit to the EPA, a project plan setting out the timeframes for construction of the Huon Gully Diversion Pond. 
The licensee must complete the following milestones related to the Huon Gully Diversion Pond by the following dates: 29 November 2024 - Construction tender scope of works. 30 December 2024 - Western Region Aboriginal Cultural Heritage Management Plan submission to the Depart of Planning Housing and Infrastructure. 25 April 2025 - Tender release to market. 28 July 2025 - Contract execution  31 December 2025 - Construction Completion.
By 14 February 2025, the licensee must submit a ‘Groundwater Mitigation and Management Report’ to the EPA including an options study outlining the future options for the following water management / operational structures: Reject Emplacement Area (REA) 'Cooks Dam'. DML Dam A-Pit, and DWP-B The report must identify the best environmental outcomes in the short, medium and long-term and into the future, post-operation of the premises to contribute towards a stable and non-polluting landform.
By 31 March 2025, the licensee must provide an options assessment which includes a suitably engineered alternative to DWP-B, – lined dirty water storage basin to prevent volume / storage loss to historical underground workings.
By 16 December 2024, the licensee must engage a suitably qualified expert to undertake an assessment of, and produce a report on a water treatment system option to treat metals discharging from the premises via LDP001, including an assessment of any appropriate concentration limits.  
By 31 March 2025, identify a suitable alternative option within the overflow area below the Huon Gully Diversion Pond, and if approval is required submit an application to DPHI by no later than 30 June 2025 for approval. Construction of the Huon Gully overflow area must commence within 3-months of the receiving the required approval.  
By 30 November 2024, monthly water quality testing must commence from the furthest point downstream of LDP001, immediately prior to the water entering Wangcol / Neubecks Creek, including but not limited to the pollutants within the Table at licence Condition M2.3 and monitoring location referred to at EPA identification number 13.
By 16 December 2024, the licensee must engage a suitably qualified expert to prepare an updated 'Site Water Management Plan' that includes, but is not limited to the following matters and notify the EPA of the identity of the expert. A revised site water balance model to estimate the discharge regime to Wangcol / Neubecks Creek (with the McPhillamys Gold Project discharge option removed). Maximising the separation of the clean, dirty, and contaminated water management systems. Minimise water discharges from the premises by maximising, where practicable, opportunities for the reuse and recycling of water on site (e.g., using high salinity water within the dirty water catchment for dust suppression).  Options for blending clean and dirty water on-site to improve the quality of water discharged from LDP001, these options should include utilisation of the DWP-A and DWP-B, following construction. A evaluation of precautionary discharge options to ensure that discharge occurs when conditions will minimise environmental impacts, or discharge during low flows. A strategy to achieve staged improvements for electrical conductivity (EC) (in addition to the pollutants within licence Condition M2.3) to minimise the salt loading and environmental impacts from LDP001 to the downstream environment. The EPA will review the proposed staging of improvements to EC and determine concentrations limits to be included within the licence. Predicted discharge concentrations of salinity and key ions. The Site Water Management Plan should also include a detailed surface and groundwater monitoring plan, to capture the intended improved outcomes. The monitoring plan must also include the new upstream and downstream monitoring locations. 
Within 1-month of the completion of the construction of the Huon Gully Diversion Pond the licensee must commence monthly water quality testing from within the Huon Gully Diversion Pond including but not limited to the pollutants within licence condition M2.3.
The water concentration limits listed in licence condition L2.4 for Point 1 above are interim and will be varied following review of the updated water management options assessment required by licence condition U1.7. Additionally, the EPA will consider implementing staged EC limits in the licence following this review.
The EPA may further vary the licence to include any appropriate water treatment operational measures identified in the report required by Condition U1.7 of the licence. 
The EPA intends to further vary the licence upon completion of U1.1 through to U1.4 to ensure all mitigation measures have been constructed generally in accordance with approved designs and are operational.