After the lethal gas was removed,Lapstone Hill Tunnel,also known as Glenbrook Tunnel,returned to what it had been before:a mushroom farm. But the tunnel’s troubles didn’t end with the war – in 2016,the then-owner of the farm was evicted due to evidence of unsafe workplace practices and environmental contamination,theBlue Mountains Gazette reported. For the past 10 years,the tunnel has been closed to the public.

Since 2023,however,the council has slowly been working towards its vision of reopening the tunnel,but Greenhill said the extent of damage and cost of remediation meant that $4 million in funding that was previously received from the state government had been insufficient to reopen it safely to the public.

The council said it has already remediated 1700 tonnes of rubbish such as mushroom farm compost material and removed 1200 tonnes of sediment from in and around the 660-metre brick-lined tunnel.

The State Heritage-listed tunnel is managed by Crown Lands NSW,and the council entered into a licence agreement with it to commence remediation works. Blue Mountains City Council is now calling on the state government to provide additional funding to complete the remaining precinct works.

“We’ve cleaned it up. We’ve decontaminated it. It’s ready for community use,but that funding goes to waste if we don’t get the extra funding to make it safe for people to access and egress,for people to park and use it safely,” Greenhill said.

Minister for Lands and Property Steve Kamper declined to respond to questions on additional funding for the activation of Lapstone Hill Tunnel.

TheSydney Morning Herald has a bureau in the heart of Parramatta. Emailparramatta@smh.com.au with news tips.