Gaping holes are being left in the land from mining operations across the NSW Hunter Valley, according to a new report calling for stricter mine rehabilitation reforms.
The report by environmental group Lock the Gate Alliance found the nine Hunter Valley mines which were assessed collectively rehabilitated 30.8 per cent of the land they disturbed with 9302 hectares of their 30,192-hectare footprint under active rehabilitation.
Ravensworth mine has rehabilitated 16.5 per cent of the land it's used while 20.4 per cent has been rehabilitated at the Bengalla mine, the report published on Sunday found.
Mines in NSW are required to undertake progressive rehabilitation throughout the life of the mine and companies must lodge a security deposit with the NSW government to cover the full costs of rehabilitation if the company defaults on its obligations.
Lock the Gate Alliance said the shortfalls are leaving gaping holes in agricultural land leaving NSW to accrue a mining rehabilitation deficit.
"Year on year, more land is disturbed than rehabilitated," the report said.
It found a key reason for the deficit is that mining companies are allowed to set their own rehabilitation targets with little or no penalties if they fail to meet them.
The anti-coal group has called on the state government to set mandatory progressive rehabilitation targets which could create additional jobs and decrease the financial liability faced by taxpayers.
"The rehabilitation shortfall in NSW means that communities are likely to end up living with the devastating consequences of, and even footing the bill for, un-rehabilitated sites," spokesman Rick Humphries said in a statement on Sunday.
The government has also been urged to prohibit final voids and waste dumps from coalmines and to ensure there's sufficient money held in security deposits for contingencies.
RMIT University Associate Professor Gavin Mudd said leaving land exposed also posed a health risk from dust pollution.
"The disturbed area of mines are a major source of particulate air pollution, which is particularly disconcerting for those communities close to densely populated areas," he said in a statement.
NSW Resources Minister Don Harwin has been contacted for comment.