The Division of Resources and Energy said the state enforced “strict conditions on all exploration and mining activity to ensure affected land is left in a safe and stable condition”.

But it did not comment on the Australia Institute’s Dark Side of the Boom report major finding – that legacy issues relating to mining will be borne by the community, and the level of currently available information made it difficult for the public to understand the extent of those legacy issues.

The DRE also did not respond to critical 2011 and 2014 NSW Audit Office reports which found there were “many thousands of hectares of degraded and contaminated lands” in NSW because of abandoned mines and the few million dollars allocated annually to their care was “substantially inadequate” to cover the liability.

The Audit Office also estimated in 2014 that there were 112 derelict mine sites on Crown Land, including 38 high risk sites and seven large scale derelict mines on Crown Land that are “potentially high risk to the environment and public health, and may need to be notified to the Environment Protection Authority”.

In a statement in response to the Australia Institute report, the DRE said the state “enforces strict conditions on all exploration and mining activity to ensure affected land is left in a safe, stable and non-polluting condition”.

“Contrary to what this report would have people believe, Government holds information on all mines in NSW and has a record of each mine’s classification and rehabilitation state,” the DRE said.

The agency conceded, in a statement quoted in the Australia Institute report, that “work is underway to collate this information into a database to make this information more accessible”, in response to Australia Institute questions on how many mines had been successfully signed off.

The report quoted the DRE noting that “very few mines have closed since the introduction of modern rehabilitation policies”, but progressive rehabilitation was expected even of mines in care and maintenance.

In its statement on Monday the DRE said mines are not identified as fully rehabilitated until they cease operation and sites are relinquished.

The DRE identified 123 mines – 55 of them coal mines – as “suspended operations” by August, 2015, but did not indicate which mines were in care and maintenance and which were unlikely to operate again, in response to Australia Institute questions.

“The DRE was unable to provide any information on how long these mines have been out of operation,” the report said.

The DRE argued the Australia Institute’s comment that “only one NSW coal mine had been fully rehabilitated”, without acknowledging the “extensive and ongoing work being undertaken to rehabilitate mines demonstrates a fundamental lack of understanding of the data and information provided by DRE”.

The DRE defended its system of rehabilitation security bonds to “cover the cost of agreed rehabilitation in full”, after criticism from analysts including Tim Buckley that the system is “untested” and leaves taxpayers exposed to significant risk.

“Mining cannot begin until this bond is received in full by the Government. If a mining company sells the site to another company, the bond must be paid before the sale can go through,” the DRE said.

It did not respond to criticism of current NSW Government acceptance of large mining voids in the Hunter as a legacy of the mining boom.

“While rehabilitation does not always require refilling a mining void, the community and landholders are consulted on the final rehabilitation conditions before planning is approved,” the DRE said.

“Since 2014 the Government has undertaken a systematic review of the calculation of rehabilitation bonds and, as a result, increased security bonds held from $1.3 billion to almost $2.2 billion by the Government,” it said.

In August the NSW Audit Office announced another review of mines, to establish whether the NSW Government maintains adequate security deposits to cover liabilities associated with mine rehabilitation, including the decommissioning of infrastructure and long term post-closure management requirements.

The audit will examine whether the Division of Resources and Energy has “a clear understanding of rehabilitation outcomes for each mine site, undertakes on-going reviews of the extent of disturbance and rehabilitation at each major mine site, maintains reasonable estimates of rehabilitation costs and can access adequate security deposits to cover the costs of rehabilitation when needed”.

Australia Institute economist Rod Campbell said the Dark Side of the Boom report was about investigating whether information on mining legacy issues was readily available – both within the department, and to the public.

“The old cliché goes that if you can’t measure it, you can’t manage it. As Australia attempts to manage the clean-up from the mining boom, it is important to see how government agencies measure this process,” Australia Institute economist Rod Campbell said.