Oil and gas producer Santos has started the approval process for its controversial Narrabri coal seam gas project in northwest NSW.

Santos on Wednesday said it had lodged its major planning assessment document for the project – the environmental impact statement – with the state government.

The company is seeking approval to drill up to 850 wells on 425 sites in and around the Pilliga state forest, with the project to deliver about 200 local jobs and $1.2 billion in state royalties over its lifetime.

The EIS concludes the project can “proceed safely and with minimal and manageable risk to the environment”.

But local communities and anti-CSG activist groups – who have fought for years to stop the “toxic” project going ahead – have criticised the latest move.

“Santos has a long, tragic history of failure in the Pilliga with at least 20 toxic coal seam gas waste water spills, including the contamination of an aquifer with uranium and other toxic heavy metals,” Wilderness Society campaign manager Naomi Hodgson said in a statement.

The group has described the lodgement of the EIS as a “desperate attempt to recoup the $1 billion it has lost on the trouble-plagued Narrabri CSG scheme” by making the asset more attractive to prospective buyers.

NSW Greens energy spokesman Jeremy Buckingham says Santos has reignited “a massive battle” in the state over CSG – which he predicts the community will win.

“Any prospective investor should get the message that we will blockade, we will disrupt and we will fight this project to the end,” he said.

Mr Buckingham, who’s urged Premier Gladys Berejiklian to clarify whether she will support the development, says the government shouldn’t allow Santos to “jerk people around, waste their time and create uncertainty just to fatten up the project for the stock market”.

Santos has sought to assure locals the project can be managed safely.

The company says it’s drawn upon more than 13,000 hours of on ground environmental surveys, considered potential social impacts and conducted thorough community and stakeholder consultation.

“The Narrabri Gas Project has the potential to play a significant role in the domestic energy space,” Santos chief executive Kevin Gallagher said in a statement.

“Natural gas has a vital role to play in delivering energy security, whilst having the additional benefit of being 50 per cent cleaner than coal resulting in a significant reduction in carbon emissions.”

Mr Gallagher said the venture could supply half of the state’s gas needs.

The NSW planning department on Wednesday confirmed it had received the application but the details of the EIS may not be made public for several weeks.