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Environ Geochem Health (2013) 35:7988 DOI 10.1007/s10653-012-9465-z
ORIGINAL PAPER
Mine tailings composition in a historic site: implications for ecological restoration
R. Courtney
Received: 15 February 2012 / Accepted: 18 May 2012 / Published online: 15 June 2012 Springer Science+Business Media B.V. 2012
Abstract Ecological restoration, using tolerant plant species and nutrient additions, is a low-cost option to decrease environmental risks associated with mine tailings. An attempt was previously made to establish such a vegetation cover on an abandoned tailings facility in Southern Ireland. Historically, the tailings site has been prone to dusting and is a potential source of contamination to the surrounding environment. The site was examined to determine the success of the previous restoration plan used to revegetate the site and to determine its suitability for further restoration. Three distinct oristic areas were identied (grassland, poor grassland and bare area) based on herbage compositions and elemental analysis. Surface and subsurface samples were taken to characterise tailings from within these areas of the tailings site. The pH of bare surface tailings (pH, 2.7) was signicantly more acidic (p \ 0.5) than in other areas. Additionally, negligible net neutralising potential resulted in the tailings being hostile to plant growth. Total metal concentrations in tailings were high(c. 10,000 mg kg-1 for Pb and up to 20,000 mg kg-1 for Zn). DTPA-extractable Zn and Pb were 16 and 11 % of the total amount, respectively. Metal content in grasses growing on some areas of the tailings were elevated and demonstrated the inability of the tailings to support sustainable plant growth. Due to the inherently
hostile characteristics of these areas, future restoration work will employ capping with a barrier layer.
Keywords Acid generation DTPA Heavy metal
Pyritic tailings Restoration
Introduction
Mining activities currently operating within the European Community are conducted within conditions dened by legislation (EC 2006/21), including the management of waste facilities with planning for the post closure rehabilitation of mine waste and monitoring, together with a nancial guarantee. However, historically abandoned and closed mine sites, operating before compliance with environmental protection standards, can potentially be a source of pollution. Poor structural stability of bare tailings can result in erosion and dust generation with potential contamination of surrounding areas.
Vegetation cover on mine wastes can achieve stabilisation, pollution...