Capita Symonds Limited
Mineral: River Terrace and Valley Gravel.
Project: Experiment as part of MIRO project Mitigating the Impacts of Quarry Dewatering in Sand and Gravel Deposits.
Planned Workings: Test abstraction well and excavations in a Replacement Minerals Local Plan Preferred Area.
Mitigation: Artificial groundwater recharge with intensive level monitoring and agreed trigger values.
Approximate Consented Reserve: N/A
Project Areas: Minerals industry research.
Chamberhouse Farm is located within an ecologically important and hydrologically sensitive area, being situated immediately adjacent to the Thatcham Reedbed Site of Special Scientific Interest (SSSI) and candidate Special Area of Conservation (cSAC).
BCL were part of the Steering Group for the project and also managed and conducted the site work. This involved testing a variety of configurations of artificial recharge trenches with respect to their efficiency in mitigating dewatering induced drawdown. Intensive monitoring was maintained allowing numerical groundwater modelling to be undertaken and highlighting some of the complexities of artificial groundwater recharge.
The experiment relied and built on earlier work BCL had undertaken at the site including an extensive monitoring record. It demonstrated that localised mitigation of drawdown in shallow sand and gravel aquifers can be provided through the use of recharge trenches and allowed conclusions to be made on the recommended design of such trenches.