The Planning Assessment Commission (PAC) Review Report handed down late last month said figures provided by mine proponent Yancoal outlining the economic benefits of the project could not be substantiated and further assessment was required.

In its original submission Yancoal claimed the extension of the mine would provide a net production benefit of between $145 and $174 million to the Commonwealth as well as State royalties of $130 million, taxes of $39 million, capital investment of $75 million and indirect output of $340 million per annum into the NSW economy.

The company also claimed an increase in the workforce at the site to 250 jobs plus an additional 464 indirect jobs and $29 million in non-market benefits of employment.

In the executive summary of its report the PAC said - following a detailed examination of the figures and with the possible exception of capital investment and direct employment at the mine - the Yancoal claims were questionable.

The commission concluded that the net production benefit to the Commonwealth was more likely to be about $23 million while royalty payments would amount to no more than $47 million.

It also said, without robust evidence to the contrary, jobs generated outside the mine site were likely to be few.

The commission said the estimation of benefits and costs were based on modelling techniques that had been severely criticised by the courts, academics, public authorities and a major economic consulting firm.

It said the estimates were based on coal prices that were so substantially above current market prices and forward pricing projections that the produced benefit estimates were simply not credible.

The commission said the current Stratford operation was already under economic pressure as evidenced by the decline in production to 1.2Mtpa (million tons per annum) of the approved 3.1Mtpa and a decline in direct employment at the mine from 125 to 71 jobs.

Yancoal was also warned it would need to address issues surrounding noise and biodiversity impacts if the Stratford extension project was to be approved.

The PAC recommended changes to  the way mine measures noise and how it reports the actions taken to minimise noise, but concluded that night-time operations should be permitted in the Avon North and Stratford East pits unless compliance monitoring indicated predictions could not be met.

The commission was also critical of Yancoal’s mitigation strategies to reduce impacts on biodiversity.