Internal government documents on the proposed F6 route and location of exhaust stacks have created alarm throughout St George and Sutherland Shire.
Many residents between Arncliffe and Gymea face an anxious wait of up to 12 months before learning whether their homes will be acquired or a smoke stack placed nearby.
Roads Minister Melinda Pavey said no decisions had been made, and a further $14.1 million was provided in this weeks budget for further planning.
Among documents obtained by Fairfax Media under freedom of information laws was one titled Tunnel Ventilation Stack Locations, dated late 2016 and marked Draft.
Locations for proposed exhaust and air supply installations included Miranda, Gymea, Arncliffe, Rockdale and Sans Souci.
Parents of students at Port Hacking High School want more details before adopting a position on a proposed exhaust stack on adjoining parkland.
The parkland, between the school and Omaru Avenue, Miranda has been a road reservation for more than 60 years.
Also nearby are St Basils aged care centre, Seymour Shaw Park and the new high-rise housing precinct.
The schools Parents and Citizens Association discussed the matter at its regular meeting on Monday night this week.
At this stage, we are prepared to wait until we can get more concrete information, president John Cox said.
Residents living around another proposed stack site in a park at the corner of Rulwalla Place and North West Arm Road, Gymea, have great concerns.
One resident, who has two young children and requested her name not be used, said she and her neighbours were very worried about the health implications.
The proposed location is at the base of a hill, where we receive little wind, she said.
There will not be adequate air flow to distribute the concentrated emissions being pumped out of the stack.
Also, I'm not an engineer, but it is quite obvious that the houses at the top of North West Arm Road, as well the residents west of the tennis courts, and also Kirrawee High School, are going to receive a great deal of pollution given the stack won't be 200 metres from their ground level.
I fail to see how this location could have been deemed appropriate for a proposed stack.
Unless their intention was to build a 300 metre high stack at this location, it leaves me questioning the competency of the engineers who proposed it.
Her husband said he wanted to see more detail, but thought emissions could be acceptable, depending on the height of the stack.
There would be some benefits in the road being in a tunnel, and they could sell of land previously acquired to help fund it, he said.
I dont care if they build it or dont build it, just so long as we have a bit of certainty.
John Thomas, who lives in Fraters Avenue, Sans Souci, opposite a proposed stack site, said he didnt want his three young children breathing all that rubbish.
I made inquiries about the F6 corridor when we bought here eight years ago and the RTA (Roads and Traffic Authority] told me it probably wouldnt be built in my lifetime and it wouldnt affect me, anyway, he said.
Roza Dimovska, who also lives opposite the proposed Sans Souci Souci stack site in an up-market medium density development, said she was not happy about it.
There are a lot of environmental and health issues, and I think it will ruin the area, she said.
Sans Souci resident Cheryl Abigail said an extension would result in significant relocation of homeowners and likely lead to protests from people concerned about its impact on nearby wetlands.
We have always known it was going to happen but this time it seems like it actually is, she said. I am probably not accepting of it but I'm of the principle of what can I do about it?
Spiro Roumeliotis accepts that the new road will one day force his family to leave because they knew about the F6 when they bought their home 16 years ago. It seems a lot closer than it ever has before, he said.
Cronulla MP and Attorney-General Mark Speakman said extensive analysis was being undertaken to ensure a huge decision like the F6 is not made back of the envelope, but is properly costed and takes into account all economic, social and environmental impacts.
No decisions have been made yet about, for example, whether to build an F6 extension and if so from where to where, location of entry/exit points along the way, underground versus overground versus a combination of both, and location of ventilation stacks if any, he said.
Mr Speakman said he expected a decision on these matters in six to 12 months, followed by community consultation and environmental impact studies before a final decision.
Modern ventilation stacks had only a negligible impact on surrounding air quality, he said.
Mr Speakman said if there was a need to use any part of the Royal National Park, it would be compensated for by additions to the park.
I expect that the government would avoid unnecessary mass acquisition of private homes and businesses, he said.
Premier Gladys Berejiklian said the government would never ever, ever, damage that precious heritage national park.
