Concerns over where the exhaust fumes from planned road tunnels will be released in Sydney are "way too premature" with projects still in early planning, the NSW premier says.
According to media reports on Monday, leaked government documents named several proposed locations for the smokestacks for the Beaches Link and the Western Harbour Tunnel, with three schools within 200 metres of some of the sites.
But NSW Premier Gladys Berejiklian said no locations had been finalised for the project and areas were still being surveyed.
"Those reports are way too premature ... we are still doing geotech studies," she said.
The proposed Beaches Link and Western Harbour tunnel would build an underground link from Rozelle to North Sydney and then tunnel under Middle Harbour to Balgowlah.
The ventilation shafts needed for the roads would reportedly need to be 25 to 35 metres tall, with the leaked documents considering smokestack locations in North Sydney, St Leonards, Cammeray, Gore Hill and Seaforth.
The plans for the route, cost and design of the project wouldn't be released to the public until the middle of 2018, Ms Berejiklian said.
"If we can do it any earlier we will, but I don't anticipate having anything more concrete to say until early next year."
Opposition Leader Luke Foley said the government was treating the community with contempt by starting "advanced planning" for the smokestacks without consultation.
"Has the government learnt nothing from the WestConnex debacle?" he said.
The government's $16.8 billion WestConnex road project has stirred opposition since its inception, with community groups and local council's raising objections.