The Rum Jungle uranium mine was a federal government-backed venture that supplied uranium to nuclear weapons programs run by the US and British governments from the 1950s to 1970s.
It was first opened in 1954, about 100 kilometres south of Darwin, and was Australia's first large-scale uranium mine.
Rum Jungle produced 3530t of uranium oxide and 20,000t of copper concentrate from four open pits until its closure and abandonment in 1971.
However, mining operations and a lack of safe processes caused "widespread environmental pollution" due to acid and metal drainage from waste rock into the surrounds.
It was not until after the mine was closed that the extent of the acid leakage and environmental damage was considered.
"Ongoing oxidation of sulphide minerals in the waste, followed by annual wet season leaching of soluble oxidation products released large concentrations of copper and other heavy metals and acid into the surrounding environment," a review in 2013 found.
The report also found vast Aboriginal sacred heritage sites had been destroyed.
An initial clean-up attempt was made between 1982 and 1986 but failed to comprehensively rehabilitate the mine sites and led to further contamination.
Now the mine is expected to cost upwards of $325 million to rehabilitate and the NT and federal governments are providing the cash to clean up the site.
So far the two governments have spent more than $25 million since 2009 on mitigating further damage and a "conceptual" rehabilitation plan has been developed.
This rehabilitation plan is being implemented and is expected to take more than onea decade to execute.
"The site's rehabilitation plan follows 10 years of detailed design work and collaboration between the Australian and NT Governments, the Kungarakan and Warai Traditional Owners, and local stakeholders," federal resources minister Keith Pitt said.
"It is aimed to maximise long-term and sustainable environmental improvements to the old mine site."
The plan involves backfilling one pit as a waste rock storage facility, with a second pit to polish site runoff before re-entering tailings. It will also involve co-localising contaminated sources and attempting to remediate impacted groundwater.
Federal minister for Indigenous Australians Ken Wyatt said the main objective of the rehabilitation was to return the site to a safe, stable, sustainable condition that supported a future land use benefitting all Kungarakan and Warai people.
