Dave Cooke The Coal Authority WAMM! Partnership (no Coal!) main - - PowerPoint PPT Presentation

Dave Cooke The Coal Authority

WAMM! Partnership (no Coal!)

• main funder and programme owners
• lead on catchment characterisation, impacts and

priorities.

• lead on scoping, feasibility, design, build and
• peration of schemes.

• 105 Water bodies affected by abandoned

metal mines

• 1500km of rivers impacted by metals

causing good status failures for chemicals

• 11% of groundwater bodies in poor status.
• 7 of 11 River Basin Districts affected.
• Fe, Ni, Pb, Cd, Cu, Zn, Al, Mn…all mined
• Approach driven by WFD, feeding into

RBMP , but no legal liability for past

• perators / current owners (of abandoned

metal mines).

WAMM! Metal Mines

WAMM! Mine Waste Directive Inventory

WAMM! and Contaminated Land Traditional contaminated land terminology: Characterisation Scoping and Optioneering Treatment Techniques Diffuse Sources Dissolved Sources Monitoring and Improvements

WAMM! Characterisations and CSMs EA Characterisation Reports Monitoring and Assessment Focus Diffuse and Dissolved Sources and Mechanisms Prioritisation and Cost Benefit Analysis

WAMM! Conceptual Models

WAMM! Conceptual Models

Optioneering – the WAMM Toolbox

Part of Scoping and Feasibility Constrained by: Geographical and Environmental Limits Mine water and spoil geochemistry Financial Political and competing policy objectives

• 75 individual waterbodies investigated, with a current

portfolio of 40+ active projects across England

• Because no legislative driver, schemes are assessed on the

basis of estimated benefits to cost ratios:

• Average for first 18 schemes B:C 3
• Top 6 schemes

B:C >5

WAMM! Works to date

WAMM! Treatment Techniques

Water (Dissolved Sources): Reaction, absorption and filtration / settling Reaction can be direct (HDS type water treatment) or indirect (VFP / VFR / HFR) Absorption (activated carbon type) Electro-precipitation (electro-chemical reaction). All based on the concentration of metals into the solid phase (with subsequent disposal / recovery?!).

Treatment continued

Solids (Diffuse sources): Typically, deposited mine spoil, erosion products (river sediments), mine processing residues. Traditional engineering techniques applicable: Containment, capping, surface water management, erosion protection. All about prevention of leaching and physical transport of solids into the water course.

WAMM! Case Studies (with the promised photos)

Saltburn Pump and Treat (Aerated Iron Precipitation) Force Crag Passive Treatment (Compost VFP) Nent Check Weirs – Dredging and New Build (Dig and Dump!) Foreshield Shaft protection (Gabion Wall) Carrshield Tailings Dam (Retaining Wall, Capping and Interceptor Drain) Wheal Jane (HDS and Clarifiers)

• Remediation of Ironstone

Mine discharge polluting stream, SSSI and bathing beach.

• £10.5 million benefits into the

local economy over the next 25 years

• Removes in excess of 98% of
• metals. (100 t Fe/year)
• Removed the risk of a

catastrophic mine water break out

WAMM! So far so good - Saltburn

Force Crag

• Worked for zinc, lead and barytes from 1835

until 1991

• Pollution affecting local becks, river and

Bassenthwaite lake. High levels of zinc, cadmium, lead and copper

• A full scale passive treatment scheme now
• perational.
• Removal of >95% of Metals

WAMM! So far so good – Force Crag

Force Crag and Coledale

Environmental Outcomes

River Nent - New check weir (Nenthall) Metals removed: forecasted 1.4t Zinc/yr Up to 60km of river improved, contributes to Tyne estuary sediments (aim to decrease from ~127t Zn/yr to <50t/yr) Scheme cost: £320k Whole life cost: £1.1m Scheme benefit: £3 - £10m (25 yrs) River Nent – Dredging existing check weirs (Nenthead) Metals removed: 20 – 30t Zn, Cd, Pb Up to 60km of river improved, contributes to Tyne estuary sediments Scheme cost: £487k Scheme benefit: £3

• £10m (25 yrs)

WAMM! So far so good – Nent Check Weirs

Environmental Outcomes

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River Nent – Foreshield shaft Metals removed: not quantified Cost: £187k Benefits: prevented river eroding metal- rich soil and being diverted into the Nent Force Level; protects calaminarian SAC River West Allen – Dressing floor diffuse pollution prevention Metals removed: not quantified Cost: £450k Benefits: together with Carrshield tailings dam, contributes up to 5% of Zn entering Tyne estuary

WAMM! So far so good – Foreshield and Carrshield

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River West Allen:

• More than 40km of river polluted with metals
• 6.5km downstream: up to 126x zinc EQS (52x cadmium)
• 27km downstream: up to 8x zinc EQS (6x cadmium)
• Up to 25% of zinc entering Tyne estuary (sediments) are from West Allen
• Fish and river flies (invertebrates) impacted for several km
• Environmental and economic benefits >£30m over 25 years
• Barney Craig mine water: key source of metals
• Carrshield tailings: significant risk of imminent collapse
• 48,000 cubic metres containing >60 tonnes zinc and 47 tonnes lead
• Scheduled ancient monument (Victorian wall, tailings in 1950s)
• Mining Waste Directive inventory: causing serious environmental harm (run-off)

WAMM! So far so good – Carrshield Tailings Dam

Carrshield Downstream

Wheal Jane Treatment Plant

Wheal Jane Consequences

Nent Haggs Passive Treatment Scheme (Water Transfer and VFP) West Allen Check Weir (Sediment retention) Coalcleugh (Surface water management and floodplain lowering) Ashfoldside Drainage Interception (Surface water management) Gwindra Pilot Scheme (4 pond gravity VFR) Tees Swale Diffuse (Green engineering and erosion control) Cambokeels Passive Treatment (In-situ VFP)

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WAMM! Future Plans

Nent Haggs Visualisation

WAMM sites in Yorkshire

WAMM! Future Plans

Environmental Outcomes

Saltburn Water treated: 0.82million m³ Metals removed: 102t of Fe 2 km of river improved. Force Crag Water treated: 65,000 m³ Metals removed: 175kg of Zn 10 km of river improved. Bassenthwaite Lake SAC now meets EQS Wheal Jane Water treated: 5.34million m³ Metals removed: 600t Cd, Ni, Zn, Cu, As, Fe 8km of watercourse improved, Fal Estuary SAC protected

WAMM! Headlines

WAMM! Ongoing

Thank You