With the industrial legacy of a former Gasworks, Platypus contained underground fill and bedrock materials beneath contaminated with substances associated with the production of coal gas, including tar and tarry wastes. Remediation of the site was the first step towards the transformation of Platypus into a new public waterfront destination.
Initial remediation involved above-ground preparations including demolition of some buildings, removal of hazardous materials, repairs to the seawall and wharf, and upgrading of underground services
The next stage of remediation involved the construction of an odour control enclosure, and installation of an emission control system and water treatment plant. Around 3,000 tonnes of tar-containing materials were excavated and removed by barge for off-site disposal.
At six storeys high, the odour control enclosure was the largest structure of its type ever constructed. 27,000 tonnes of material remained for on-site treatment and stabilisation. This material was then used to backfill the excavated area and to create a mound capped with clean soil, forming the base for the landscaped park at the northern end of Sub Base Platypus.