But proponent Santos is unlikely to begin widespread exploitation of the mineral for a number of years, in part due to rigorous conditions imposed by the Independent Planning Commission, opponents claim.

The controversial $3.6 billion coal seam gas plan won final state government approval - on more than 130 conditions - on Wednesday.

Now, the project is in the hands of the Commonwealth Minister for the Environment, Sussan Ley.

Under the Environmental Protection and Biodiversity Conservation Act, the minister has 30 business days to approve the project following formal receipt of the NSW Government's assessment report.

That timeline can be extended under the Act if the minister asks.

In a statement to the Leader, Minister Ley said "matters of environmental significance", like water resources, "are rigorously assessed under national environmental law".

The 20-year-old gas project has long been controversial, partly due to community concern about its potential impact on water aquifers.

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Hundreds of community members and experts spoke to the Independent Planning Commission in a record seven-day public hearing about the project. Almost all of them opposed it.

In a series of questions sent to Minister Ley, the Leader asked if she will take into account community views when making the approval.

"The Commonwealth will consider the findings of the NSW Government's assessment," she said.

Santos was contacted for comment but did not respond.

Lock the Gate Alliance spokesperson Georgina Woods said the company may not make a final investment decision on the project before 2023.

"As usual for these projects there's a great deal of work for Santos to do until they can begin," she said.

"One of the things I was pleased to see in the consent was the commission specifying Santos must update their groundwater model to the highest confidence level before they can proceed to production.

"We're talking about sort of two years from now before a decision is really available to them to make about proceeding to production and that's if the groundwater model has been updated by that time.

"Given how rapidly the ground is shifting on the energy market front here and around the world...

"Anybody who says they're confident about where things will stand in two or three things for the gas industry is just taking a stab in the dark."

In a statement on Wednesday, the company's Managing Director and Chief Executive Officer Kevin Gallagher said the company accepts the conditions of the IPC.

The company will now work with the Federal Department of Agriculture, Water and Environment as it considers its recommendation to the Minister on EPBC Act approval, it said.

Key to this recommendation will be that the NSW assessment process has adequately addressed all relevant matters of national environmental significance, Santos said.