rivers and mining: can they co-exist?
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CRICOS code 00025B
Rivers and Mining: can they co-exist?RiverTalk June 2021
Sue VinkSustainable Minerals InstituteThe University of Queensland
An Old AllianceSustainable Minerals Institute
Copper Age, Bronze Age5000 years mining in Rio Tinto, Spain
Paleo river channels with deposits-Banded Iron FormationsPilbara Iron Ore
Gold Rush
Rivers impacting minesFlooding
Rivers impacting minesWater quality affecting mine production
Chili River before and after treatment plant
Bacteria in water reduces copper recovery
Mines impacting rivers – Direct Impacts
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Sustainable Minerals Institute
CHANGES TO RIVER FLOW WATER QUALITYRELEASES MINE AFFECTED WATER – SALTS, ACID MINE
DRAINAGE, METALS, ETC
TAILINGS SPILLS, SEEPAGE RIVER DIVERSIONS
Mines impacting rivers – Direct Impacts
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Sustainable Minerals Institute
River Flow 1. Alternative Sources:Groundwater, lower quality water, seawater, treated waste water
2. Increased water re-use:70% freshwater savings in Queensland coal mines
3. Process optimisation:New Polymers and Reagents, water quality changeEvaporation control
4. Dry Mining
Water critical for mining60% water is from groundwater
Mines impacting rivers – Direct Impacts
Sustainable Minerals Institute
Tailings spills, Dam failure, seepage
Minas Girais, Brazil. 2019
Ok Tedi & Fly rivers, PNG 1984 – 2007,
90 M tons waste discharged/yr1000 km river 30 km2 forest dead
Mines impacting rivers – Direct Impacts
Sustainable Minerals Institute
RIVER DIVERSIONS
Goonyella Riverside, QldMcArthur River, NT
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Sustainable Minerals Institute
Mines impacting rivers – Indirect Impacts
Ocoña shrimp fishery supplies the entire nation.
Ocoña River, Peru: Proposed hydropower to support mine expansion
CRICOS code 00025B
Case study 1 Hunter River Salinity Trading schemewww.water.nsw.gov.au
What does the HRSTS aim to do?
Manage saline water discharge (from point-sources: coalmines and power stations) to minimise impact on irrigation and other water uses, and the environmentTo achieve this at least cost to the community, in an equitable and flexible way, through financial incentives to reduce saline water pollution
Keep EC <600 uS/cm on Hunter river @ at Denman, and EC< 900 uS/cm on Hunter River u/s Glennies Ck, and on Hunter River @ SingletonLicensed discharges can only occur when flows are greater than 2000 ML/D at Singleton
How it worksUses best available River science to develop the schemeInvested in research where uncertainties existedCollaboration between mines, state government and other stakeholders since 2002
Based on dilution principle – as flows increase, salinity decreases, and the river can safely absorb salt discharges without exceeding set limits
HRSTS in ‘rest’ mode until rainfall event occursif flows >2000 Ml/D at Singleton for a min block of 24 hours, with flows > 1000ML/D at Denman, and > 1800 ML/D at Hunter u/s Glennies Ck
Total Allowable Discharge (TAD) calculated
River Register issued – gives authorisation to discharge
Why it works• Uses best available River science to develop the scheme
• Investment in research where uncertainties exist
• Collaboration between mines, state government and other stakeholders
• Transparent allocations and accurate records who has discharged what/when
• Highly reliable monitoring network
CRICOS code 00025B
Case study 2 Fitzroy Partnership for River Healthwww.riverhealth.org
Background
• Ongoing community concern over impact of mine discharges on river water quality (salinity)
• Data lacking? • Mines (and government) held
large quantities of data but paper
• data quality and accuracy, questionable
No window of opportunity
1 day
Larger and greater complexity
Vision:is that the Fitzroy Basin community is informed by a coordinated monitoring approach that communicates basin-wide waterway health to actively support improved management across all users
Partnership of community, mines, industry, agriculture, scientists, government
Independent science panel
River water quality and ecology monitoring network (conducted by mines under compliance)• Improve monitoring, extends existing network, independent presentation and analysis• Produce annual river health report cards• Where data is lacking, best scientific judgement is used• Selected key variables monitored: i.e. not monitoring everything everywhere• Adaptive monitoring will be reviewed as new data is acquired
Fitzroy Partnership for River Health
How the ecosystem grade is calculated
https://riverhealth.org.au/resources/grading-explained/freshwater-and-estuary/
Evolution of monitoring design
RREMP Sites &EA release point sites
Existing regulated monitoring
Consider fundamentals river science:• Flow timing and volumes• Water quality drivers and interactions• Biology• Recognise complexity
Invest in science Understand the mine in the context of the river
system/catchment
Understand other mines and other stakeholders in the catchment (i.e. Cumulative Impacts)
CollaborationTransparencyTrustCommon Language
Best practice mining and rivers
