Case study:Force Crag Mine Remediation: Difference between revisions
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{{Case study status | {{Case study status | ||
|Approval status= | |Approval status=Approved | ||
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{{Location | {{Location | ||
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|Main contact id=HPotter | |Main contact id=HPotter | ||
|Contact organisation=Environment Agency | |Contact organisation=Environment Agency | ||
|Partner organisations=The Coal Authority (UK), Defra | |Partner organisations=The Coal Authority (UK), Defra, National Trust, Newcastle University | ||
|Multi-site=No | |Multi-site=No | ||
|Project picture=800px-2014 April completed Force Crag scheme - John Malley.jpg | |Project picture=800px-2014 April completed Force Crag scheme - John Malley.jpg | ||
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We've been working in partnership with the Coal Authority, the National Trust and Newcastle University to develop a remediation scheme for this site with funding from Defra. The ‘vertical flow pond’ designed by Newcastle University is the first of its kind in the UK and uses compost, limestone and woodchips to remove metals from the water without the need for added energy or chemicals. This passive system works by passing the mine water down through the compost mixture where microbial activity binds the metals as sulphides, before discharging through a small wetland and into the Coledale Beck. | We've been working in partnership with the Coal Authority, the National Trust and Newcastle University to develop a remediation scheme for this site with funding from Defra. The ‘vertical flow pond’ designed by Newcastle University is the first of its kind in the UK and uses compost, limestone and woodchips to remove metals from the water without the need for added energy or chemicals. This passive system works by passing the mine water down through the compost mixture where microbial activity binds the metals as sulphides, before discharging through a small wetland and into the Coledale Beck. | ||
In September 2013, the Coal Authority began building the treatment scheme within the existing bunding of the former tailings lagoon. The National Trust and English Heritage supported the scheme as the next stage in the life cycle of this historic industrial site. On 31 March 2014, the valves were opened and mine water started filling up the ponds. | In September 2013, the Coal Authority began building the treatment scheme within the existing bunding of the former tailings lagoon. The National Trust and English Heritage supported the scheme as the next stage in the life cycle of this historic industrial site. On 31 March 2014, the valves were opened and mine water started filling up the ponds... | ||
The system has now been operating for a year, and has removed over half a tonne of zinc. Although we're only treating some of the mine water flow (6 l/s), it's already making a significant difference to the water quality in the Coledale Beck since the scheme is removing >95% of the zinc, and >90% of the cadmium and lead. This is not yet enough for the river to achieve good status but we hope Bassenthwaite Lake will no longer fail the EQS for metals. Over the next couple of years we will see if the treatment system can cope with more of the flow without harming performance, and investigate how to deal with diffuse sources of metals in the catchment. | |||
The benefits of cleaning up the Force Crag mine water are estimated to be up to £4.9m over 25 years, at a cost of~£1.5m. | |||
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{{Image gallery}} | {{Image gallery}} | ||
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{{Case study subcatchment}} | {{Case study subcatchment | ||
{{Site}} | |Subcatchment=Newlands Beck | ||
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{{Site | |||
|WFD water body code=GB112075070440 | |||
|WFD water body name=Newlands Beck | |||
|Heavily modified water body=No | |||
|Protected species present=No | |||
|Invasive species present=No | |||
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{{Project background | {{Project background | ||
|Works started=2013/09/02 | |Works started=2013/09/02 | ||
|Benefit to cost ratio=Benefits of cleaning up the Force Crag mine water are estimated to be £1.6m - £4.9m over 25 years, at a cost of ~£1.5m | |||
|Benefit to cost ratio= | }} | ||
{{Motivations | |||
|Specific mitigation=Historic mining activities | |||
|Physico-chemical quality elements=Nutrient concentrations, Oxygen balance, | |||
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{{Measures | |||
|Floodplain / River corridor=Vertical flow pond which uses compost, limestone and woodchips to remove metals from the water without the need for added energy or chemicals | |||
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{{Hydromorphological quality elements header}} | {{Hydromorphological quality elements header}} | ||
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Latest revision as of 13:24, 6 June 2017
Project overview
Status | In progress |
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Project web site | |
Themes | Habitat and biodiversity, Water quality |
Country | England |
Main contact forename | Hugh |
Main contact surname | Potter |
Main contact user ID | User:HPotter |
Contact organisation | Environment Agency |
Contact organisation web site | |
Partner organisations | The Coal Authority (UK), Defra, National Trust, Newcastle University |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
Force Crag mine, worked for zinc, lead and barytes until 1991, was famously the last working mine in the Lake District. Mine water discharges and diffuse pollution from waste heaps mean it's a major source of cadmium, zinc and lead, depositing around 3 tonnes each year into the watercourse. The metals pollute the Coledale Beck and the Newlands Beck as far as Bassenthwaite Lake, and prevent these water bodies achieving good Chemical and Ecological status for the Water Framework Directive.
The site is now owned by the National Trust and run as a visitor attraction. It's within the Lake District High Fells SAC and two SSSI’s; Force Crag mine itself and Buttermere High Fells. It is also a Scheduled Monument.
We've been working in partnership with the Coal Authority, the National Trust and Newcastle University to develop a remediation scheme for this site with funding from Defra. The ‘vertical flow pond’ designed by Newcastle University is the first of its kind in the UK and uses compost, limestone and woodchips to remove metals from the water without the need for added energy or chemicals. This passive system works by passing the mine water down through the compost mixture where microbial activity binds the metals as sulphides, before discharging through a small wetland and into the Coledale Beck.
In September 2013, the Coal Authority began building the treatment scheme within the existing bunding of the former tailings lagoon. The National Trust and English Heritage supported the scheme as the next stage in the life cycle of this historic industrial site. On 31 March 2014, the valves were opened and mine water started filling up the ponds...
The system has now been operating for a year, and has removed over half a tonne of zinc. Although we're only treating some of the mine water flow (6 l/s), it's already making a significant difference to the water quality in the Coledale Beck since the scheme is removing >95% of the zinc, and >90% of the cadmium and lead. This is not yet enough for the river to achieve good status but we hope Bassenthwaite Lake will no longer fail the EQS for metals. Over the next couple of years we will see if the treatment system can cope with more of the flow without harming performance, and investigate how to deal with diffuse sources of metals in the catchment.
The benefits of cleaning up the Force Crag mine water are estimated to be up to £4.9m over 25 years, at a cost of~£1.5m.
Monitoring surveys and results
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