2021 Feb: Contamination Fears due to Tunnelling under Middle Harbour (Sydney, NSW)

‘Our kids play school sports nearby’: Locals fear contamination from new tunnel


Feb 19 2021

Contaminated sediment from the bottom of Middle Harbour will be dug up for a new harbour tunnel, prompting community groups to raise concerns about potential environmental damage to the waterway as well as surrounding bushland and residential areas.

The environmental impact statement for the Beaches Link tunnel, which is on public exhibition until March 1, confirms that sludge from Middle Harbour contains PFAS chemicals and heavy metals such as mercury and lead.

Tributyltin, a toxic chemical banned after it was found to cause female sea snails to develop male sex organs and become sterile, has also been detected.

Temporary dams will be erected in Middle Harbour during the building of the tunnel between Northbridge and Seaforth, which require the excavation of sediments that present “a high contamination risk to construction”, the EIS said. Other excavation sites associated with the multi-billion dollar tunnel project present a moderate contamination risk.

A Transport for NSW spokesman said the Beaches Link would be built according to strict conditions of approval, including “strong mitigation measures”.

He said the proposed construction methods for the tunnel had been used safely around the world to protect sensitive waterways.

“The tunnel alignment has been designed to take advantage of the deeper water in Middle Harbour and minimise the amount of dredging required,” he said.

Transport bureaucrats would also stage work and consider ways to reduce noise and minimise dust during construction, such as using portable barriers and watering techniques, he said. “The community can be assured Transport for NSW will continuously monitor the local environment during design and construction.”

President of the Willoughby Environmental Protection Association John Moratelli said there were “serious questions” about whether the spread of dangerous sediment could be controlled by the measures proposed.

The community group is also concerned about the destruction of bushland; the loss of habitat for vulnerable species; and contamination risks from disturbing the old tip at Flat Rock Gully.

Mr Moratelli said the risks associated with the tunnel weren’t justified and the project had “meagre and doubtful long-term benefits” compared to other road projects.

The Sydney Morning Herald last week reported that sludge in Sydney Harbour containing “alarming” levels of toxins would be dug up during construction of the Western Harbour tunnel.

Ravi Naidu, the director of the Global Centre for Environmental Remediation at the University of Newcastle, said dredging Middle Harbour presented similar risks to the Western Harbour tunnel project.

Professor Naidu said the EIS had revealed the presence of toxic chemicals that could pose a “significant risk” to workers and the public unless the dredging process included appropriate measures to minimise risks.

“While we focus on how construction workers ought to minimise risk during the dredging process especially with the management of dredged material, one would also need to see what could be done to clean potentially contaminated sites that are the source of subsurface contamination,” he said.

Willoughby Council has also highlighted a number of concerns about the tunnel project in its response to the EIS, which will be considered at a meeting of councillors next month.

Areas of concern include noise and vibration, airborne contaminants, emissions from ventilation stacks, potentially contaminated land as well as biodiversity and habitat loss, a council spokeswoman said.

“If the project proceeds, government must apply the lessons learned from other such projects to ensure the best outcomes for the community,” she said.

Larissa Penn, a spokeswoman for the Coalition of Tunnel Concerned Communities, said the risks associated with the construction of the tunnel had not been fully assessed.

“Our kids play school sports nearby, swim at Northbridge Baths and Clontarf and go out on the Harbour and the health risk assessment hasn’t considered the baths, impacts of runoff or the probability of a spill,” she said.

Ms Penn also expressed concern about the impact of the construction on residents including noise, dust and heavy vehicle movements.

“Major infrastructure shouldn’t put communities, the environment and workers at unreasonable risk and benefits should clearly outweigh the full range of costs,” she said.