Removal of lead contaminated peat, and follow-up contour bunding, at Ballynahone

Tender description

Ulster Wildlife is seeking a quote for remediation of an area of lead contaminated peat at Ballynahone Special Area of Conservation (SAC) in County Derry. Ballynahone Bog is a 245 ha reserve approximately 2km south of Maghera, Co Derry. It is protected by a number of designations; it was declared an Area of Special Scientific Interest in 1994 and a SAC (UK0016599), under the EU Habitats Directive, in 2005. Most of the reserve, including the area of lead contamination, is managed by Ulster Wildlife under a lease with the Department of Agriculture Environment and Rural Affairs. Up to 5 tonnes of lead may have been deposited when Ballynahone was used as a clay pigeon shooting range between 1966 and 1986 (EHS 2004). Concentrations of other metals associated with clay shooting (e.g. arsenic, antimony, cadmium, chromium, copper and nickel) and some polycyclic aromatic hydrocarbons are present but at lower levels (EHS 2004) .The lead is affecting c0.4ha of the ASSI, is being taken up by plants, is migrating off site and may, particularly following rain, move into groundwater and/or the Moyola River. Various options have been considered to deal with this ranging from no action to construction of an artificial drain to channel contaminated surface water to a treatment area onsite. The preference is for complete removal of lead contaminated peat from the area and subsequent safe disposal of that lead at a toxic waste facility. The work is in three phases: removal of adjacent wooded vegetation to allow machinery access to the contaminated area; excavation, removal and subsequent safe disposal of contaminated material; contour bunding and levelling of site to <0.5% to facilitate subsequent restoration and return to active peat formation. A site visit has been organised for Tuesday 12th October and you are asked to contact trish.fox@ulsterwildlife.org by noon on Monday 11th October 2021 to book in. Budget is £82,000 ex VAT and works must be completed by 28/02/2022