Briefing note: impact on the ecosystems of Sydney Harbour

There are several immediately obvious problems with the EIS when it comes to marine contamination:

  1. Non-disclosure of concentrations and location of contaminants in sediment, as outlined above.
  2. Failure to flag contamination with the EPA, as required by Contaminated Land Management Act.
  3. Nowhere in the entire EIS is the potential impact on important public recreational assets such as the Dawn Fraser Pool, or Greenwich Baths, both heavily used by young families, addressed. What will be the impact of contaminated marine sediment disturbance on these vital facilities?
  4. The EIS cites outdated guidelines, not current guidelines in relation to marine sediments.

The Environment Impact Statement (EIS) relating to the Western Harbour Tunnel/Beaches Link project is a document constructed so as to obfuscate the very real contamination risks posed by long-present toxins on the harbour bed, particularly in the once heavily industrialised areas of Birchgrove and Berry’s Bay. References to the presence of toxins appear to be deliberately veiled, fleeting and scattered in a relatively random way through a document more than 250 pages long.

The project, as currently proposed, would see prefabricated sections of the proposed harbour crossing laid in a shallow trench across the harbour from Birchgrove to Waverton. Disturbance of marine contaminants would be an inevitable outcome of creating both the trench, and constructing  two massive so-called “coffer dams” from which all water has to be removed, exposing the sea-bed to enable connection of the tunnel to the prefab crossing sections. 

The EIS goes out of its way to avoid acknowledging the presence of contaminants in harbour sediment. For instance, the technical working paper says:

Contamination has been reported in sediments present within Sydney Harbour. Contamination is likely to be associated with inputs from the surrounding urbanised catchments, historical industrial operations and the general maritime use within the harbour. The sediments pose a high contamination risk to construction given that contamination is known to be present within sediments which are likely to be excavated and exposed during construction of the Sydney Harbour south cofferdam (WHT5) and Sydney Harbour north cofferdam (WHT6)

EIS Technical Working Paper, p. 2

But the presence of toxic sediments in the areas proposed for excavation/disturbance has long been well documented, for example in this paper by leading expert, Gavin Birch and others.   

Buried at the back of the EIS is a technical working paper, Appendix  M, entitled Contamination. Its table 4.2 states that ‘potential” contaminants include  “Heavy metals, hydrocarbons (mainly Polycyclic aromatic hydrocarbons (PAH)), pesticides, PCB, dioxin, organotins, per- and poly- fluoroalkyl substances (PFAS)” . More information about what was found in the sediments is at p.56 and 57,of Appendix M among other places.

Geochemist Bill Ryall is a remediation specialist who has worked for the NSW government and was a site auditor accredited by the NSW Environmental Protection Authority. He has reviewed Appendix M and the EIS report itself and found that the EIS should have, but does not reveal the distribution or concentration of the contaminants in the marine sediment which will be disturbed by the proposed method of construction. Therefore it is impossible for the SEARS (Secretary’s Environmental Assessment Requirements) to be met as the EIS stands. It is a serious problem that, in Bill Ryall’s words, “[the EIS] does not provide any indication of the seriousness of the contamination in sediments in the Immersion Tube Tunnel Corridor or in White Bay.”

it is impossible for the SEARS (Secretary’s Environmental Assessment Requirements) to be met as the EIS stands.

The cocktail of chemicals present include dioxins (human carcinogens and often referred to as “ gender benders”), heavy metals , especially mercury, which is toxic both to human health and the marine ecosystem, and TBT ( tributyl tin) among others, TBT also being potently toxic to the marine ecosystem.

Critically, Jamie Parker MP sought information from the Western Harbour Tunnel “team” inside the Department of Transport. On expert advice, he included the question, “What are the concentrations of the various chemical substances in the sediment that will be dredged?”

But the request was denied.

Instead he was told, in a response from Jacqueline Smith ( principal manager communications – Western Harbour Tunnel Beaches Link Infrastructure and Place. Transport for NSW) that:

“This information forms part of a commercial in confidence procurement process and for probity reasons cannot be released at this time.”

Jacqueline Smith ( principal manager communications – Western Harbour Tunnel Beaches Link Infrastructure and Place. Transport for NSW)

This email can be provided.

Bill Ryall has managed more than a dozen remediation major remediation projects, including at Homebush Bay. He says never before has he seen “commercial in confidence” used as an excuse to deny the provision of such information. There is the additional point that tenderers will have to be given this information in order to tender accurately. So how can it possibly be “commercial in confidence”?

This is the non-disclosure issue.

The EIS cites outdated guidelines, not current guidelines in relation to marine sediments. Appendix M says that “Sediment sampling was carried out within the proposed Sydney Harbour crossing and construction support sites at White Bay (WHT3) and Berrys Bay (WHT7) as part of the DGPA (December 2017a) investigation. Sediment samples were collected from a range of depths and analysed for contaminant compounds including heavy metals, TRH, BTEX, PAH, OCP, PCBs, per- and poly-fluoroalkyl substances (PFAS), dioxins, OPP, organotins, dioxins and furans, ASS, cyanide, nutrients, pyrethroids, chorobenzenes, carbamates, phenols, herbicides, volatile chlorinated and halogenated hydrocarbons and radionuclides. The results of the laboratory analysis were compared against the following guideline criteria: ANZECC (2000) High and Low Interim Sediment Quality Guidelines (ISQG)” (p. 56). But those 2000 guidelines are completely out of date. Current guidelines, which are from 2013, should have been cited.

This document was prepared by the WHTAG community group.

Further Resources

This brief document highlights the most obvious, but by no means all, the fundamental flaws in the marine sediment sections of the EIS. For further information see: