The Northern Territory Government has today released details of individual environmental security bond amounts held for nine major mines.

Security bonds are held in the event a company is unable to clean up after itself once production on a mine ends or is prematurely terminated.

It is a blow to the mining industry which has argued the amount of the respective bonds must not be made public, as it would harm the competitiveness of operators and deter investment.

But while NT Minister for Resources Ken Vowles acknowledges the security bond information was previously kept secret and regarded as commercial in confidence, he said there was a need for greater transparency.

Posted this morning on the Department of Primary Industry and Resources (DPIR) website, financial amounts for nine mine sites have been released totalling more than $1.2 billion.

The largest bond is held for the bauxite mine at Nhulunbuy, operated by Alcan Gove, totalling $650,928,464.

The lead, silver and zinc McArthur River mine near Borroloola has the second largest bond held at $476,094,542.

The smallest bond listed on the DPIR website is $53,250 for the Edna Beryl gold mine at Tennant Creek which recommenced operation this year.

The mothballed Cosmo gold mine near Adelaide River, owned by Kirkland Lake Gold, has $6,374,012 held, and the ilmenite mine near Mataranka, owned by Australian Ilmenite Resources, has $445,795 held.

The director of the Mount Todd gold mine north of Katherine said making security bonds publicly available would have an effect on future mining investment in the Northern Territory.

Vista Gold director Brent Murdoch said the Territory was the first jurisdiction to do so to this extent, which would discourage competitiveness.

But he said other states would likely follow the Territory’s lead, and other investment opportunities in the Territory would outweigh the negative effects.

“There are many other factors up here in the Northern Territory that make the Northern Territory such an attractive prospect,” Mr Murdoch said.

“I think in the short and medium term, those factors will certainly outweigh this.”

Mr Murdoch said explaining how the bonds were calculated was just as important as making the bonds public.

“It’s a very detailed calculation and the effort and the expertise that goes into that I think is not known by many, and when that’s known we’ll have the trust in the community going forward,” he said.

Emmerson Resources, which runs a small gold mine in Tennant Creek through a tribute agreement with the Edna Beryl Mining Company, said the release of information would be especially hard on small operators.

Managing Director Rob Bills said the public should be content with having the total amount of bonds held released only — a figure of more than $1.3 billion.

“Disclosing is great on the one hand, but on the other it creates a lot of concern and work on our side,” he said.

“For a little company like Emmerson we have to put our bonds up on our website, which we’ve done, and it just creates more paperwork, more work for us being a very small company, if you get a lot of enquiries.”

According to Mr Bills the bonds, published on their own and without context, could create a misconception about the industry from the public.

“[There’s] no sort of set calculation on how those bonds were set,” he said.

“We’re an exploration company, our environmental footprint is incredibly small.

” What the public will see is probably quite a disparity in the sort of bonds from different companies and different operations, [and] they may not understand actually how they were calculated.

“A lot of the industry opponents can create a lot of community concern around some of these things.”

According to the company’s 2016 annual report, Emmerson’s bonds for its activities across the country total $1,028,328, while according to the Department of Industry and Resources, the Edna Beryl figure sits at $53,250.