Envirotreat was commissioned to design a remediation strategy (Marine Sediment E-Clay stabilisation) to facilitate maintenance dredging at Killybegs Harbour.
The prime contaminants of concern preventing disposal at sea were tributyltin [TBT] and dibutyltin [DBT], in addition, hydrocarbon pollutants were also present in some of the samples tested at low levels.
The identified TBT and DBT concentration levels ranged from 0.003mg/kg – 54.3mg/kg (3ug/kg – 54,300ug/kg) and 0.004mg/kg – 1.43mg/kg (4ug/kg – 1430ug/kg) respectively.
Following the successful bench trials undertaken by Envirotreat, the proposed E-Clay formulation was utilised in the treatment of dredged sediments.
The validation requirements were primarily
focused on compliance with agreed leachate
target values for TBT / DBT.
The agreed leachability target value for TBT / DBT was 200ng/l (0.2ug/l). Supplementary Waste Acceptance Criteria [WAC] testing was carried out on the treated materials to confirm suitability for use at the disposal site for restoration purposes.
On completion of the works, Envirotreat prepared a comprehensive Validation Report.