This report has been prepared on behalf of and for the sole use of Mardie Minerals Pty Ltd and is subject to and issued in accordance with the agreement between Preston Consulting Pty Ltd and Mardie Minerals Pty Ltd. Preston Consulting Pty Ltd accepts no liability or responsibility whatsoever. for or in respect of any use of or reliance on this Report by any third party. Copying of any part of this Report without the express permission of Preston Consulting Pty Ltd and the Mardie Minerals Pty Ltd is not permitted.
Mardie Minerals Pty Ltd (Mardie Minerals) (Applicant) is currently developing the Mardie Project (the Project) located in the Western Pilbara region of Western Australia (WA), approximately 80 kilometers (km) south west of Karratha in the town of Karratha. The project currently operates an approved 80-man temporary exploration camp (20 x 4 bedroom accommodation blocks) which was approved by the Department of Mines, Industry Regulation and Safety (DMIRS) in April 2019 under a works approval (Reg ID: 79508). The temporary camp currently operates a smaller packaging plant for sewage treatment, which has a design capacity of less than 20 m3/day, which is less than the requirements for a prescribed facility.
This requires the camp to be expanded to temporarily accommodate up to 200 people (total) during periods of peak activity, and an additional work program application has been submitted to DMIRS for the expansion of the camp from 80 to 200 people. Mardie Minerals will address the increase by installing two additional 20 m3/day package handling plants to complement the existing package plant. The proposed extension of the sewage treatment plant peak capacity to 60 m3/day requires a Works Approval (category 85) under the Environmental Protection Act 1986 (EP Act) and related regulations.
This document contains the attachments as required by the Department of Water and Environmental Management (DWER) Application Form: Approval / Permit / Extension.
PRESCRIBED PREMISES MAP
An expansion of the capacity of the existing temporary treatment plant from less than 20 m3/day to 60 m3/day. The capacity increase will ensure that the wastewater treatment requirements of the expanded exploration camp (up to 200 person peak capacity) will be adequately addressed and will ensure that the treated wastewater is suitable for land irrigation in accordance with WA Department of Health and Australian and New Zealand Environment requirements and Conservation Council (ARMCANZ) and Agriculture and Resource Management Council of Australia and New Zealand (ANZECC) water quality guidelines (1997). The proposed two new treatment trains will replicate the existing activated sludge bioreactor (ASBR) treatment plant.
Screened effluent will be held in balance tanks prior to treatment to ensure that the ASBR process receives a constant flow that is within its design limits. The chlorine detention tank where treated effluent is dosed with chlorine and held for a suitable period of time to ensure that biological activity falls below output limits and class C treatment is achieved (ARMCANZ and ANZECC, 1997). Thickened biological floc (sludge) retrieved from the clarifier is digested to reduce volume, with a portion of the sludge recirculated back to the aeration tank to restart the process.
The irrigation area will be one hectare (ha) over loam as defined in Australian Standard 1547:2012 On-site management of domestic wastewater. The fence shall be at least five feet from the sprinkler spray pattern to ensure that any spray drift is contained within the exclusion zone. The exploration camp, including the WWTP, is located at E08/1849, with a small portion of the sprinkler irrigation field located at E08/2740 (Figure 2).
Access to the camp is from the North-West Coastal Highway, via the Mardiesteasi access road. The area surrounding the exploration camp and WWTP is predominantly spinifex grassland used for cattle grazing under the Mardie Pastoral Lease, which is held by Citic Pacific Mining through its subsidiary, Pastoral Management Pty Ltd (PMPL). Extensive areas of bare salt pans are located immediately west of the camp, with the coastal coastline approximately 8 km away.
Mardie Homestead is the only other pastoral lease accommodation and is used by station staff. The level of use of the homestead and associated buildings fluctuates according to the level of activity at the station. The risk to Mardie Pool from the proposed treatment plant is considered to be negligible.
An additional two processing trains will be manufactured off-site and trucked to the premises. They will then be assembled and installed next to the existing ČN on the same leveled surface, increasing the physical footprint from approximately 100 m2 to approximately 250 m2.
OTHER APPROVALS AND CONSULTATION
Other Approvals
- Part IV Environmental Protection Act 1986
- Part V Environmental Protection Act 1986
- Mining Act 1978
- Health Act 1911
Stakeholder Consultation
This works approval application will be advertised for public comment in accordance with DWER's standard procedure. As described in Table 4, controls during the construction, commissioning and operation of the WWTP research camp expansion will minimize the risk of emissions affecting the environment. The receptors are located a considerable distance from the camp WWTP and are not expected to be affected (see Appendix 7 for further details on the location and location of the proposed facilities described).
SITING AND LOCATION
PROPOSED FEE CALCULATION
