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TERRAMIN AUSTRALIA Limited. Angas Zinc Project. Water. Topics Water sources Outcomes Risk identification, management, control Mine water demand Modelling (groundwater) Monitoring. MARP Outcome & Criteria. Outcome
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TERRAMIN AUSTRALIA Limited Angas Zinc Project
Water • Topics • Water sources • Outcomes • Risk identification, management, control • Mine water demand • Modelling (groundwater) • Monitoring
MARP Outcome & Criteria • Outcome • No adverse impact to the supply of water to existing users and water dependent ecosystems • Criteria • Water to be measured for metals, flow, depth and organic content. All measurements are compared to baseline data.
Management Strategy ZERO DISCHARGE POLICY No contaminate water to leave site All engineering design and placement of infrastructure is set to achieve: ZERO DISCHARGE
Water Sources Sources of water • Rainfall • Permanent surface water • Ephemeral surface water • Ground water • Waste water
Water sources • Mine is Eastern Mount Lofty Ranges, part of the prescribed surface water area and Murray River Catchment, adjacent to Angas-Bremer prescribed wells area • Waters in the location of the mine • Burnside Creek (ephemeral) • Angas River • Aquifers: shallow and deep • Surface water runoff (storm events) • Flood plains (storm events) • Council Sewage Treatment Ponds
Water users Regional • Users of Angas Catchment - surface & groundwater • Users of Lake Alexandrina water Local • Two current properties have shallow bores • Mains water • Waste water from Lagoons - Polo Club, Olive grove
Management Actions • TSF - lined - Zero discharge • Water storages - lined dams - Zero discharge • Surface water management - clean/”dirty” separated - designed for ARI 1:100 • Waste water lagoons - low permeability rocks & thick crown pillar • Underground & surface process water contained within circuit. • Underground - no flow out to environment – draw-down whilst pumping • If large flows encountered we would pressure grout the walls
Mine water balance • Mine will not discharge water • The site is net water negative, with balance of requirements coming from potable supply source (SA Water) • Looking at Reverse Osmosis to reduce SA Water demand
Effluent Ponds • Mine dewatering may intercept some infiltration of sewage ponds, adjacent to Tuckers Swamp • Management: required for high E.Coli and faecal coliforms (measured) - health risk • Current users of effluent – Polo club, Olive grove
Groundwater modelling • AWE: Rick Aldam • Principal Environmental Scientist • Groundwater draw down modelling • To define any cone of depression of groundwater that is undergoing extraction
2 Rain Water circuits1 circuit for water that has contacted mining surfaces1 circuit for uncontaminated surface water
Ambient water typical levels • Plot of metals in drill holes
Ambient water typical levels • Plot of TDS & pH in drill holes
Management Target ZERO DISCHARGE POLICY No contaminate water to leave site All engineering design and placement of infrastructure is set to achieve: ZERO DISCHARGE