Public submissions for the two mine expansions close on June 9 and then PAC consisting of chair Gordon Kirkby, Lynelle Briggs and Garry West will make a final decision on the two projects.

Mr Kirkby and Ms Briggs sat on the original PAC review that included two days of public hearings in Singleton in December last year.

Bulga Milbrodale Progress Association (BMPA), through the NSW Environment Defenders Office, has made a request for a two-week extension for public submissions.

BMPA spokesman John Krey said the two weeks currently available to make submissions on the projects was simply too little time for a proper report to be prepared by the organisation’s experts.

“Our main concerns are the government’s and the company’s refusal to properly look at the PAC’s request to investigate the suggestion to relocate Bulga,” he said.

“Also, how the company is allowed to get away with no absolute guarantee on the regeneration of the Warkworth Sands Woodlands – because now if they fail years down the track they simply hand over $1 million for an ecological community that is extinct.”

Rio Tinto spokesman said in the Department of Planning's review of the PAC its states the bond is intended as an additional incentive to ensure Warkworth commits adequate resources to the WSW restoration in a timely manner.

"In the event that the restoration does not meet the performance criteria after 15 years, the $1milliom bond would be forfeited and Warkworth would still be required to complete the restoration works," the department's assessment report states.

If you wish to comment on the department’s recommendation, email your comments to the PAC on pac@pac.nsw.gov.au before 5pm, Tuesday, June 9, 2015.

Or, post or fax your comments to the commission at GPO Box, 3415, Sydney NSW 2001; or fax (02) 9299 9835, but please ensure they arrive by 5pm on June 9.