THE CHALLENGE:
Historically the site has been used as a tar distillery and timber treatment yard – coal tar products were transported to/from the site by boat on the tidal river. Site investigations indicated the tidal foreshore area of the site was heavily contaminated (and evident at surface) with metals, polycyclic aromatic hydrocarbons and petroleum hydrocarbons.
The objective of the remediation works was to remove the contaminated sediment from the foreshore including the area above high water and the intertidal zone of the Eling Channel. The contaminated soil straddled the foreshore with some lying above the high water mark and some below.
OUR SOLUTION:
Source removal was completed by removal of the contaminated sediments from site by excavation and off-site disposal to a suitable landfill facility. The excavated areas were then restored with imported clean sediments with physical properties closely matching the original, and the foreshore area was restored with clean capping materials and subsequently seeded. Works had to be carefully sequenced to allow safe excavation / reinstatement between tidal cycles, and contaminated waste waters had to be carefully managed.
Following successful completion of the primary remediation works, Soifix was awarded a repeat contract to undertake remediation works on the adjacent terminal site. Preliminary remediation works were undertaken to areas of identified gross NAPL contamination to mitigate acute risks, through targeted excavation and disposal of buried drums containing coal-tar liquids, pilot-scale and longer term NAPL skimming from recovery trenches/sumps and undertaking pilot treatability trials on excavated coal tar/creosote contaminated soils using ex-situ bioremediation methods.
