The ESB subsidiary Hibernian Wind Power has denied that undue pressure was placed on the blanket bog environment in the Slieve Aughty mountains of south Galway, following last week's landslide in the area.
The company has suspended all construction work at its 71-turbine wind farm at Derrybrien for a week, pending investigations by its consultants into the cause of the peat slide. A spokesman has confirmed that several small incidents involving machinery had occurred on the site over the past month, while contractors were trying to meet deadlines for the project.
The mountain of peat and soil, which rolled down 1,500 metres through adjoining Coillte property on Thursday, was estimated to have moved another 30 to 40 metres at the base at the weekend. A temporary defence was constructed by Galway County Council to prevent further shifts, but there is concern locally about the effect of this defence when rain falls.
No one was injured in the initial slide, which occurred in dry weather when 70 contractors, attached to the wind farm project and to Coillte, were working on site. The slide halted at an unoccupied house close to the Derrybrien-Loughrea road.
The movement occurred just a month after the landslide from Dooncarton mountain, north Mayo, which forced more than 40 families to evacuate their homes in Pollathomas.
Staff at Shannon Regional Fisheries Board have been checking the impact of the slide on watercourses linking Lough Cutra and also feeding into the Shannon.
Mr Martin Collins of Derrybrien Concerned Residents Association, which had opposed the development of wind farms in the area, has called for an independent investigation into the landslide. "If we get rain now, we are heading for serious disaster in relation to pollution on the watercourses," Mr Collins said last night.
Construction of the 60 megawatt wind farm on a 350-hectare site began last July, under three separate sets of planning permission which had been acquired by the site's owners, Saorgus Energy of Kerry. Work on two of the project's three phases had been halted, pending application to the council for an extension to existing planning permission, a spokesman for Hibernian Energy said last night. Planning permission for the third phase applied to the end of next year, he said.
An Bord Pleanála overruled the council's refusal of an application by Saorgus Energy to extend the number of wind turbines on the site. The council was granted permission for 46 turbines, but refused permission in December 2000 for an additional 25.
An NUI Galway geologist, Dr Mike Williams, who has researched bog movements over previous centuries, has said that a prolonged dry period can cause such slides. Under such dry conditions, peat can perish and roots holding it to the bedrock can shrivel up. Dr Williams has warned that further bog slides in mountainous areas could occur with the advent of heavy rain over the next few weeks.