Six new exhaust stacks for Sydney's south for proposed F6 Extension

Fairfax Media has obtained limited access to details of the places planned for the stacks. The document, titled "Tunnel Ventilation Stack Locations", was produced in late 2016 and has the word "Draft" on the front cover.

It identifies six locations for ventilation stations, exhaust stacks and air intake pipes in Arncliffe, Rockdale, Sans Souci, Kogarah and Port Hacking. It doesn't make clear whether other locations are under consideration.

Without exhaust stacks and ventilation buildings for pumps and machinery there could be no tunnels and the F6 Extension would be unable to fulfil its promise of avoiding 60 sets of traffic lights between the Princes Highway at Loftus and St Peters.

Other material seen by Fairfax Media indicates that the proposed motorway between Sydney and the Illawarra can achieve the promised reductions in travel time only if it goes through the Royal National Park or land obtained by acquiring and bulldozing 460 homes and 40 commercial properties between Loftus and Waterfall.

A document released under the Government Information (Public Access) Act refers to a cabinet directive not to consider public transport alternatives to the motorway including a rail option that would cut the time taken to travel from Wollongong to Central by train from 90 minutes to little more than one hour.

A response to a Public Access Act application says information about the locations for the exhaust stacks was included in a document that was submitted to cabinet.

An exhaust stack and air supply stack are planned opposite the south-eastern end of Valda Avenue and on the north-western corner portion of Kogarah Golf Course. The ventilation building would have a footprint of about 1000 square metres. The shafts would be near residents of Marsh Street and Valda Avenue as well as residents of a proposed 5000-home development on the current site of the Kogarah Golf Club.

The Rockdale Wetlands would host a ventilation station located between Fairway and Annette avenues and directly opposite Civic Avenue. The ventilation station would take up between 1500 and 2000 square metres. Directly below would be the F6 Extension tunnel. It appears to be on a site now used for playing fields.

A ventilation station with a footprint of about 2500 square metres and an exhaust stack would be placed on the south side of Fraters Avenue, Sans Souci, between Dorrigo Lane and the car park of St George Sailing Club. Depending on wind conditions, a relatively new medium-density residential development directly north of the club would also be affected.

A ventilation station with a footprint of almost 2500 square metres and the associated exhaust stack and air supply stack is planned on the east side of West Botany Street between Bermill and Bay streets opposite Rockdale Plaza. The land is at present occupied by retail outlets including the Heritage Building Centre, the Salvos Store and Plus Fitness 24/7.

One ventilation station would be on vacant land next to Port Hacking High School between the main buildings and Omaru Avenue. The other will be at an existing park near Rulwalla Place and NW Arm Road.

John Cox, president of the Port Hacking High School Parents and Citizens Association said the school had long known that the F6 corridor ran alongside it, but had until recently believed the freeway would be above ground.

"We only started to get an inkling it would be a tunnel when they started doing some drilling for what they said were geological purposes," he said. "But we have heard nothing about a tunnel or nothing about a smoke stack."

The exhaust from the tens of thousands of vehicles that would use the tunnel every day would escape into the air 150 to 200 metres from the school classrooms.

Mr Cox said the land was occasionally used by the school for orienteering and other activities and had in the past hosted visiting circuses.

Asked about the stack locations a spokesman for Roads Minister Melinda Pavey said no decision had been made on the corridor for an F6 extension.

"Reports that the government plans to build a road through Royal National Park or acquire homes for the extension are completely premature," he said. The community would be kept informed at key stages of the project.

The Liberal member for Cronulla, Mark Speakman, said the F6 represented the missing link between Sydney and Wollongong and work needed to begin on it "sooner rather than latter" because of increasing congestion.

But Mr Speakman, who is the state's Attorney-General, said he would demand that the size of the National Park be maintained or increased by acquiring bushland elsewhere if the F6 encroached on park land.

"I would be putting a very strong case that we cannot see the park decrease in size," he said. "I would certainly object to doing anything to the national park that didn't have that counterbalance."

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With Matt O'Sullivan