The Grassmoor Country Park site was formerly six lagoons created within spoil tips associated with the extensive workings of the former Grassmoor colliery. The lagoons were historically used for the treatment of effluent from the former Grassmoor gasworks and coking plant. After the decline and eventual demolition of the Grassmoor coking plant, the lagoons continued to treat effluent from the nearby Avenue coking plant. Derbyshire County Council eventually took ownership of the land. An estimated 50,000 m³ of coal tar remained in the six lagoons.
RemedX was invited to tender on a design-and-build basis using a competitive dialogue procurement method. The council appointed RemedX to remediate the tar lagoons as the principal contractor. The company completed ground investigations and pilot trials. Then, a full environmental impact assessment was prepared to support the planning submission for remediating the site.
A key aspect of the planning work involved refining the conceptual site model and risk modelling to determine site-specific target levels that would be protective of open-space end-use and the nearby brook running through the country park. Particular attention was given to the assessment of the remediation treatment options and air quality. RemedX was able to utilise the comprehensive range of services that its parent company RSK offers to gain planning and regulatory approvals for the design as part of a collaborative project team. RemedX submitted the planning application and the planning committee granted permission. During the planning process, RSK’s ecological team identified a badger sett, which was successfully relocated to a new, purpose-built sett outside the working area.