Such a staggering investment, even for a company with the backing of China’s state-owned Shenhua Group and its seemingly endless supply of money, demands a return.

The case prosecuted across the 6000 pages of its environmental impact statement has won over the NSW Department of Planning and Environment and another dozen government authorities.

“On balance, the department believes that the project’s benefits outweigh its residual costs,” the department concluded in a document recommending the coalmine’s approval.

Now, the company has just one more authority – the independent Planning Assessment Commission (PAC) – to convince before it can extract 268 million tonnes of coal buried beneath 4000ha of land near Breeza.

The vast majority of the 77 speakers registered to address the PAC’s three panellists at its hearings in Gunnedah on Thursday and Friday will be doing their best to scupper Shenhua’s plans.

Arguments will range from the scientific to the emotional across issues such as air quality, noise and groundwater, but all strands will inevitably lead to the same conclusion: it would be lunacy to allow coalmining on the productive Liverpool Plains soils.

Shenhua Watermark’s project manager Paul Jackson is adamant that despite the controversy, the mine is “definitely a good story for the Gunnedah region”.

“We’ve done the scientific work that shows we can co-exist with agriculture and it shows that we won’t do any damage to the alluvial aquifers,” he said.

“We’ve followed the process, we’ve respected the process. 

We’ve done everything we’ve been asked to do, including what the community’s asked us to do.”

The mine’s potential socio-economic benefits, not just to the region but the state, are immense, according to Shenhua’s projections.

One billion dollars in turnover for each year of the 30-year operation, 600 jobs during construction and another 600 during production – with workers “required to live locally” – an $18 million community fund and $1.5 billion in state royalties.

“This far exceeds the regional benefits associated with continued use of the site for agricultural land use (i.e. about 40 jobs and $5 million in annual business turnover),” the Department of Planning and Environment has noted.

Above all else, though, the key to the company’s confidence lies in its mapping and modelling of the complicated network of aquifers in and around the project’s target area.

Using data collected from more than 100 groundwater monitoring sites, Shenhua maintains its activities will have no lasting impacts on the water-rich aquifers surrounding th mine, the majority of which are located five or more kilometres away.

“As far as we’re concerned, it almost gets to the stage where you start to run out of independent experts (supporting the project) in Australia,” said Shenhua Watermark’s environmental manager, Mark Howes.

Whatever arguments are put forward against the project during the PAC meetings this week, Shenhua is confident it has the answers.

“At the end of the day, people are going to have their opinions about this project,” Mr Jackson said. “We’ll rely on the science and we’ll rely on the facts, not the rhetoric.”