The clean-up proposal involves treatment of contaminated soil to destroy dioxins and other contaminants. The dangerous levels of contaminants in the Bay have resulted in the current fishing ban on the Parramatta River west of the Gladesville Bridge and in Homebush Bay. Contaminants in the Bay include dioxins and furans, organochlorines and PCBs, polyaromatic hydrocarbons, phenols, chlorinated phenols, heavy metals and phthalates. The potential toxicity due to the mixture of compounds present in the sediments is of great concern. Phthalates and heavy metals are present in highest concentrations adjacent to the ICI site and dioxins and other organic chemicals are present in the highest concentrations adjacent to the former Union Carbide and Allied Feeds sites.
Concentrations generally decrease with distance from the sites.
The current clean-up proposal for the Bay involves removing some of the sediments and treating them to remove contaminants such as dioxins. Remediated sediment will then be placed on land. The proposal, however, currently lacks any plans for the validation of remediation of the sediment by means of bio-assays. A new sea wall is proposed to stop recontamination of the Bay from adjoining sites not fully rehabilitated in the proposal. Currently the proposal covers only a small part of the Bay, and does not include the area adjacent to the ICI site.