Transcript Slide 1

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
Catchments map
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 water balance
In (m³/h)
Out (m³/h)
Fresh
8.4
Tailings moisture
Mine water ingress
7.2
Evaporation
0.2
Effluent
0.3
Water stores evaporation
0.3
Weighbridge
0.1
Concentrate moisture
1.3
Total in
15.6 Total out
13.4
15.6
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
Groundwater modelling
draw-down
2 Rain Water
circuits
1 circuit for water that
has contacted mining
surfaces
1 circuit for
uncontaminated surface
water
Surface
water
monitoring
Ground
water
monitoring
(plus TSF – 9 bores)
Ambient water
typical levels
• Plot of metals in drill holes
Zinc
Arsenic
0.1
1.8
0.09
1.6
0.08
1.4
0.07
1.2
mg/l
mg/l
0.06
0.05
0.04
1
0.8
0.6
0.03
0.02
0.4
0.01
0.2
0
0
AN 93
AN 43
AN 79
AN 40
AN 95
AN 47
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AN 43
AN 79
Hole#
AN 40
AN 95
AN 47
Hole#
Fluride
Lead
0.9
14
0.8
12
0.7
10
0.5
mg/l
mg/l
0.6
0.4
0.3
8
6
4
0.2
2
0.1
0
0
AN 93
AN 43
AN 79
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Hole#
AN 95
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AN 93
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AN 79
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Hole#
AN 95
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Ambient water
typical levels
• Plot of TDS & pH in drill holes
pH
TDS
10
25000
9
8
20000
7
6
pH
mg/l
15000
5
4
10000
3
2
5000
1
0
0
AN 93
AN 43
AN 79
AN 40
Hole#
AN 95
AN 47
AN 93
AN 43
AN 79
AN 40
Hole#
AN 95
AN 47
Management Target
ZERO DISCHARGE POLICY
No contaminate water to leave site
All engineering design and placement of
infrastructure is set to achieve:
ZERO DISCHARGE