S Walsh & Sons Limited
Mineral: River terrace sand and gravel.
Project: Planning application for quarrying and inert landfill.
Planned Workings: Full depth dewatering of mineral during operations. Voids infilled with inert waste.
Mitigation: Groundwater quality and level monitoring with agreed trigger values and contingency mitigation. Restoration landform shaped to form a secondary flood defence.
Approximate Consented Landfill Capacity: 2,100,000 cubic metres of inert waste.
Project Areas: EIA, HRA, PPC, FRA.
East Tilbury Quarry Landfill is situated upon the Thames floodplain, adjacent to Mucking Flats and Marshes (SSSI, SPA and Ramsar status). The economic mineral and underlying Thanet Sands constitute a Secondary (Minor) Aquifer. The Upper Chalk (beneath the Thanet Sands) is classed as a Principal Aquifer, supporting public water supply.
Extensive data collection, routine monitoring over several years, computer-based modelling works and discussions with the Environment Agency were undertaken by BCL to assist S Walsh & Sons Limited in securing planning permission for placement of circa 2,100,000 m3 of inert waste at East Tilbury Quarry Landfill.
The implementation of the treatment systems, engineering measures and monitoring protocol advanced by BCL have ensured that best available solutions (not incurring excessive costs) have been provided for protecting the water environment against the risks associated with the recycling and landfill of inert waste.
BCL’s Flood Risk Assessment showed that the raising of land levels through the Site restoration proposals would impact upon floodplain storage capacity. As mitigation for this potential impact, BCL advised that the restoration landform should be shaped to form a secondary flood defence giving better protection to the village of East Tilbury.
EIA: Environmental Impact Assessment.
HRA: Hydrogeological Risk Assessment (in accordance with EA LFTGN01)
PPC: Pollution Prevention & Control Permitting.
FRA: Flood Risk Assessment.