Sydney Students Clean Up Agent Orange Chemicals

By Shannon Corvo

Topic: Water Pollution

Sunday, 31 May 2026, at 7:12 am

Over 50 years after the Vietnam War, students are removing Agent Orange chemicals from a Sydney waterway.

Homebush Bay was an industrial area for herbicide and pesticide production during the 20th century.

US company Union Carbide made 2,4,5-T and 2,4-D for the Vietnam War, ingredients in Agent Orange.

Union Carbide worked in Rhodes from 1928 to 1986.

The mixture had dioxins, which cause health issues in humans.

The US used Agent Orange to reduce food and shelter for the enemy.

Between 1962 and 1971, the US sprayed Agent Orange over southern Vietnam.

Agent Orange was used as a defoliant in the Vietnam War.

It covered 3 million hectares of land and 20,000 villages.

3 million Vietnamese people got sick from Agent Orange, with cancers and deformities.

Union Carbide worked in Rhodes from 1928 to 1986.

This is an aerial view of Rhodes peninsula and Homebush Bay.

Smells and spills were common in Rhodes.

Sharon Weismantel first visited Rhodes in 1986 when Union Carbide was closing.

She moved in with her husband in 1987, with 275 residents nearby.

You could smell chemicals from the factories.

A spill at Union Carbide affected the leaves on hydrangeas.

This is a photo of the Union Carbide site in 1984.

Union Carbide was asked for comment by the ABC.

Ms Weismantel's father-in-law worked at CSR Chemicals, which had spills.

The environmental team could not find the spill because it went through the soil.

The soil was like layered chocolate mud cake.

Union Carbide's problem was when it reclaimed land in Homebush Bay.

The company dumped toxic waste into the bay, covered it with soil, and repeated the process.

If you look at old photos, you can see the Rhodes peninsula changed.

There were concerns that dioxins were getting into the harbour.

A clean-up in 1993 failed, and hopes to build an athlete's village for the Olympics were dashed.

Another clean-up started in 2004 with a commercial-government partnership.

This is Homebush Bay in Rhodes in 2026.

When the rubbish layers were exposed, a terrible smell spread.

The soil was dug up and heated to remove contaminants.

The successful clean-up finished in 2011 and cost $200 million.

Toxic dioxins were found in Sydney's fish.

Dioxins are highly toxic and accumulate in the food chain.

Dioxins from the old factory site were found in the harbour.

A fishing ban started in 2006 due to high dioxin levels in fish.

A university student, Dylan Freeman, is working on a bioremediation project.

Bioremediation uses microorganisms to remove toxins from contaminated sites.

The team is trying to create a method that can be used at any site.

The team is refining an existing bioremediation technique.

Traditional methods involve digging and pumping large volumes of water.

Using nature against itself is a new approach.

The students collected a sample of sediment from Homebush Bay.

They found bacteria that had adapted to the dioxins.

Two bioremediation researchers are working at Homebush Bay.

They grew more of the good bacteria and injected it back into the site.

After three months, the dioxins had decreased significantly.

Once dioxins break down, the ecosystem will recover.

Ms Weismantel thinks the project is interesting but has questions.

The solution might not reach far enough, especially with the mangroves.

More NSW news is available.

Analysis by Matt Brann is provided.

Analysis by Sean Rubinsztein-Dunlop is available.

The topic is weather.

The time is Sunday, 31 May 2026, at 7:12 am.

The time is Sunday, 31 May 2026, at 10:09 am.

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