An investigation into the ecological status of metalliferous mine tailings sites in Counties Galway, Sligo and Tipperary

Abstract

Metalliferous mining in Ireland is a multi-million pound industry and its operations are a "far-cry" from the first Bronze Age workings. With the modern industry however, comes the production of large quantities of mine tailings. These are composed o f waste rock containing residual heavy metals, uneconomic minerals, water and chemicals and must be managed in a way that will not pose a threat to the environment. The conventional management process involves pumping the mine tailings, in slurry form, into a constructed pond where, over time the water is decanted leaving a material high in metals but devoid o f the elements necessary for its stabilisation. Rehabilitation of this material is necessary to prevent pollution but also to convert it to an aesthetically pleasing state. This study investigated the existing status o f five metalliferous mine tailings sites in Ireland, to determine the degree of rehabilitation at each. These sites are located at Tynagh, County Galway, Abbeytown, County Sligo and Gortdrum, Shallee and Silvermines, County Tipperary. Abbeytown and Shallee underwent natural colonisation while managed rehabilitation took place at the other sites. Results from studies undertaken between 1990 and 1994 indicate that natural or managed rehabilitation o f the five mine tailings sites was taking place. Abbeytown mine tailings site, which was naturally rehabilitated, appeared to be the most successfully rehabilitated site. It was felt that no assistance was required to enhance the rehabilitation process there. In relation to the other sites it was felt that further assistance may be required to ensure long term stabilisation.