The impacts of mining on the Glengonnar Water, Leadhills, South Lanarkshire. Scoping Study November 2011 Page 1 The Coal Authority Impacts of Mining on the Glengonnar Water November 2011 This report has been prepared by the Coal Authority for SEPA as part of a co- funded project under the SEPA restoration funding to assess the impact of metal pollution on the Glengonnar Water. Any other party using this information should seek permission from SEPA and the Coal Authority. Any conclusions or recommendations made are those based on information obtained for the report and our current knowledge and practices. Data used within the report; either obtained by the Coal Authority or 3rd Party data has been cited within the report. Any limitations of the data are indentified within the report. The Coal Authority does not accept liability for the accuracy of any 3rd party data. Should new data or information become available these results, conclusions and recommendations may require amending. The report should only be used in the stated context. VERSION ORIGINATED CHECKED APPROVED Final Lee Wyatt Alex Norton Stuart Rolley The Coal Authority Impacts of Mining on the Glengonnar Water November 2011 Executive Summary Mining and its associated processes have long been a feature of the area surrounding the Glengonnar Water. Contaminants from this mining legacy have had a significant impact upon the quality of the watercourse and surrounding area. This pollution means that the Glengonnar Water does not accord with the quality requirements of the Water Framework Directive. The Coal Authority undertook a part funded scoping study lasting from November 2010 to end of March 2011 to determine the extent and magnitude of the contamination and provide potential options for the remediation of the area. The data collation during the study and from various 3rd party studies shows there is significant pollution of the Glengonnar Water from heavy metals including Lead, Zinc and Cadmium present as particulate and dissolved states within the water. The study highlighted a significant source of the Lead pollution is due to the presence of Lead in the alluvium and approximately half the Lead is as particulate Lead. Thus, it has been recommended that prior to any remediation of the mine water inputs the contamination in the floodplain and surrounding alluvium is assessed for remediation. Samples taken from the floodplain and surrounding alluvial material indicate there is significant contamination in the form of Lead, Zinc, Cadmium, and Copper. Measurements and observations of the flows from various mine water discharges indicate a seasonal pattern and occasionally the Glengonnar Water is made up predominantly of these mine water emissions. Water levels and observations of the mine water drainage levels indicate build up of approximately 20m of water within the Gripps level and a head of over 50m present in the mine workings giving a potential risk of ‘blow-outs’ of mine water from the Gripps Level. An initial study in to the upper parts of the Wanlock Water; an adjacent catchment suggest there is also significant contamination of heavy metals including Lead, Zinc and Cadmium; hence it has been advised a study is undertaken in to the Wanlock Water and an assessment made of the chemistry status of the waterbody. The Coal Authority Impacts of Mining on the Glengonnar Water November 2011 Contents 1. Background 2. Aim 3. Waterbody Status 4. Topography, Hydrology and Geology 5. Mining 6. Conceptual Model 7. Data Collation and Results 7.1 On site and datalogger results 7.2 Results from laboratory analyses 8. Data Analyses 9. Conclusions 10. Recommendation 11. References Appendices Appendix 1 Photographs of monitoring sites and mining features Appendix 2 Site visit sheets Appendix 3 Collated on site data Appendix 4 Collated laboratory data Figures Figure 1.1 Location map Figure 2.1 Photographs of the potential inputs to the Glengonnar Water Figure 2.2 Photograph of the Glengonnar Water (south of Leadhills) Figure 3.1 Water body information (water body information sheet 10116 (Glengonnar Water)) Figure 3.2 Extract from waterbody information sheet 10116 (Glengonnar Water) Figure 3.3 Pressures and Measures (waterbody information sheet 10116 (Glengonnar Water)) Figure 4.1 Topographic map of the area Figure 4.2 Principle mineral veins Figure 4.3 Geological plan Figure 5.1 Location map of mining features Figure 5.2 Diagram of mining methods Figure 5.3 Photograph of Gripps Level and air shafts Figure 5.4 Photograph of Straitsteps mine Figure 5.5 Photograph of Susanna Vein Figure 5.6 Photograph of Upper Glengonnar Water Figure 7.1 Glengonnar Water monitoring points Figure 7.2 Wanlock Water sample points Figure 7.3 Graph of mine water levels for Glengonnar Water (OS – On Site manual reading) Figure 7.4 Graph of mine water flow monitoring for the dataloggers Figure 7.5 Graph of mine water flow monitoring for the manual readings Figure 7.6 Graph of logger temperature Figure 7.7 Graph of logger conductivity for the mine water flows The Coal Authority Impacts of Mining on the Glengonnar Water November 2011 Figure 7.8 Graph of conductivity measurements throughout Glengonnar Water Figure 7.9 Graph of Lead concentrations for Glengonnar Water Figure 7.10 Graph of Zinc concentrations for Glengonnar Water Figure 7.11 Graph of Cadmium concentration for Glengonnar Water Figure 7.12 Map of Lead concentrations for Glengonnar Water Figure 7.13 Map of Zinc concentrations for Glengonnar Water Figure 7.14 Map of Cadmium concentrations for Glengonnar Water Tables Table 7.1 Summary table of on site measurements Table 7.2 Summary table of laboratory analyses Table 7.3 Summary table of soil sample analyses The Coal Authority Impacts of Mining on the Glengonnar Water July 2011 1. Background The village of Leadhills in South Lanarkshire (see figure 1.1) has long been acknowledged as the centre for Lead mining in Scotland. Mining is thought to have occurred as early as 1239, with the majority taking place between 1600 and the 1930s when metal mining took over this area of South Lanarkshire (e.g. SEPA, 2008). The remnants of this major industry can be seen throughout this part of the catchment with spoil heaps and mining features dominating the landscape. Whilst there is a visible reminder of the areas mining past there is also an unseen pressure on this catchment; water from the mining legacy. Mine water and mine wastes containing elevated quantities of Lead, Cadmium and Zinc discharge into the Glengonnar Water causing pollution of a 10km stretch from Leadhills to the River Clyde at Abington. SEPA has identified the Glengonnar Water as being under pressure from mining inputs and restoration targets have been set for the water body. The overall chemical status within the River Basin Management Plan is ‘Fail’. The water body fails to meet the standards set for the UK Specific Pollutant Zinc and the Priority Substances Lead and Cadmium. During mining in order to safeguard the mineral reserves and to ensure dry working conditions within the mine a series of drainage levels were installed. These carried water from the mine to local watercourses. This was long before the quality of local watercourses was monitored. Even though mining ceased some 80 years ago these drainage levels continue to discharge water from the mines to the present day. It is thought that roof collapses within these drainage levels has resulted in mine waters being forced to surface and discharging from abandoned shafts alongside the Glengonnar Water. There are numerous points at which mine waters enter the Glengonnar Water, either through the drainage levels or as the result of mine water resurgence from the numerous shafts (see section 5). Since 1994 the Coal Authority has been monitoring and treating water from coal mining sources. The Authority currently has 55 mine water schemes throughout the UK with 14 of these being in Scotland. The Authority has a longstanding and successful relationship with SEPA which is regulated by a formal Memorandum of Understanding. To date, the Coal Authority has carried out three major projects throughout England and Wales to investigate water from metal mines, working with the Environment Agency, DEFRA and the Welsh Government. Page 1 The Coal Authority Impacts of Mining on the Glengonnar Water November 2011 Figure 1.1 Location map. Page 2 The Coal Authority Impacts of Mining on the Glengonnar Water November 2011 2. Aim Currently, discharges from non coal sources have no responsible person and as a result attainment of WFD ‘Good’ status by 2027 will be difficult to achieve. The Coal Authority have been encouraged by SEPA, following a similar exercise for DEFRA and the Welsh Government, to investigate the problems associated with the mine water from the metal mines in the Leadhills area. This scoping study is a precursor to a more detailed feasibility study which would present treatment options which can be progressed in the future with a view to treating the Glengonnar Water and achieving an elevated status within the watercourse. Figure 2.1 – Photographs of the potential inputs to the Glengonnar Water SEPA have monitored the Glengonnar Water for many years but due to a limited number of monitoring points, one upstream and one 5km downstream of the study area, it was not possible to pinpoint the sources and pathways of the pollution. This report will analyse the mine water inputs, the sediment and inputs from the extensive spoil heaps and any other sources which line the Glengonnar Water between Leadhills and Abington. It is assumed that the mine water drainage levels are one of the main contributors to the downgrading of the watercourse due to their direct connection to the mine workings which are now flooded, with the water carrying Lead, Zinc and Cadmium from the mine.