Remediation of former tannery site by E-Clay stabilisation.
Site Background & History.
The site was previously occupied by a tannery, the tannery was believed to be operational from the 1830’s to the 1960’s. The site was being redeveloped for residential use by
Bellway Homes.
Arsenic concentrations on site typically ranged from 4,000 – 8,300 mg/kg with the highest concentration being 46,100 mg/kg.
Remediation Strategy
Three remediation options were considered:
- A cover system (capping layer) to address human health concerns and to isolate the surface layers from the underlying contaminated soils / groundwater
- Excavation and removal from site
- On-site treatment by E-Clay Stabilisation
Envirotreat carried out treatability trials to determine the optimum stabilisation medium for treating the identified pollutants.
Remediation works
The proposed strategy involved the ex-situ remediation of 6,500 m3 of contaminated materials.
The contaminated materials were excavated and stockpiled prior to E-Clay treatment.
Validation
Following treatment, soils were stockpiled. Validation samples were submitted for total and leachable contaminant analysis. Analysis was compared to the agreed remediation target criteria.
A comprehensive Validation Report was prepared on completion of the remediation works.
