Port Augusta’s 200m-tall chimney stack toppled to complete Northern Power Station demolition

In a slow-motion descent that culminates in an explosion of dust and debris, Port Augusta’s 200m-high landmark chimney stack comes tumbling down — see the demolition here.

• Alinta Energy reveals $200-300m committed to remediate site
• Port Augusta residents protest for further remediation of power plant
• Dust clouds cause breathing issues for residents

Port Augusta’s 200m-high iconic chimney stack has been toppled, signalling the end of a two-and-a-half year demolition process at the Northern Power Station.

Standing 68m taller than Adelaide’s Westpac building, explosives were used on Friday morning to fell the structure at the coal-fired power station, formerly owned by Alinta Energy, which closed in May 2016.

Explosives at the base of the stack trigger the collapse.

Flinders Power, which now owns and is decommissioning the site, planned to fell the chimney in April, but postponed works to further develop a contingency plan with ElectraNet.

“The main transmission line is about 80m away from the stack, so in the unlikely event it fell the wrong way, it could’ve impacted supply to the west coast,” Flinders Power chief executive Peter Georgaris said.

“The consequences, even though unlikely, were high.”

Mr Georgaris said the $200-$300 million committed by Alinta Energy towards the power station’s remediation was sufficient.

He said six 10,000-tonne shipments of scrap had already been taken to Port Pirie to be exported overseas and another shipment was expected before the remediation is complete.

“If we can complete that (remediation) process in early 2019, the other area we’re exploring is future uses for the site,” Mr Georgaris said.

“They’ve ranged from alternative electricity generation options ... as the site is adjacent to the transmission of the Davenport substation you can plug in easier.

“It’s also being considered for other industrial purposes and we’ve retained the railway line to give people flexibity to explore all options.

“There is an opportunity to open it up to fishing access, but that won’t be for some time from a safety point of view.”

Mr Georgaris said the station’s entire 273ha ash dam — which during strong winds caused breathing issues for residents — was with topsoil and remediation progressing well.

“Revegetation is progressing albeit slower than expected, but it’s consistent with the below-average rain events,” he said.

“Despite that an area we were able to cover early last year and which had rainfall has significant growth and we’re starting to see an ecosystem develop there.”

He said dust suppressant trials had identified a successful suppressant for high-risk areas, which absorbs into the surface but still allows rain to permeate through to feed plants.