This project involved bulk excavation, remediation of soils and restoration work at Venn Quarry.
Following its closure in 2006, the site was sold to the Habitat First Group and planning permission approved to develop the site into an eco-friendly nature-based holiday community. This contract would fulfil a ROMP restoration landform comprising of a partial backfilling of both Bailey’s and Spear’s Pits, using approximately 496,000m3 of fill material sourced from within the site.
The fill comprised of approximately 202,000m3 of rock and 293,000m3 of quarry spoil obtained through excavation, drilling, blasting and crushing operations to produce a suitable fill.
The backfilled materials were then capped (76,000m3) and overlain by 130,000m3 of soil forming material sourced from off site and formed in two distinct layers – 0.5m layer of imported clay rich soil (Class 2) with no potential for acid generation (pH neutral) and low course material content and 0.5m of soil forming material to suit the requirements of the Landscape Management and Aftercare Scheme and to comprise of 200mm of topsoil and 300mm of underlying subsoil.
Extensive drainage works were also carried out including the relocation of water treatment facilities, construction of three treatment ponds and an attenuation basin with an outfall built to discharge water back into the river following treatment.
Further works included the construction of buttresses to strengthen and reinforce the quarry walls, installation of temporary haul roads to the quarry summit and removal of 250m3 of invasive plant species.
