In its response to Santos's 7000-page environmental impact study (EIS), the council detailed its outstanding concerns about the CSG project, including how the company planned to dispose of as much as 42,000 tonnes of salt per year the project will produce at its peak.

"I wouldn't want that going to landfill," said Tony Meppem, council planning director, noting the town's current landfill site - located five kilometres from Narrabri - is only licensed to take 12,000 tonnes of general waste annually.

The council's recommendations to the Planning Assessment Commission include clarification that treated water produced from CSG wells will not contain hydrocarbons. The PAC should also examine what steps Santos can take to reduce cadmium levels to meet national health standards rather the five-times the threshold limit implied in the EIS.

Mr Meppem said the government "likes to absolve itself" of responsibility for checking environmental impacts, noting dust monitoring from nearby coal mines was left to miners themselves rather than the Environment Protection Authority.

With a project as complex as this one - with as many as 850 CSG wells planned over 95,000 hectares - the government needed to ensure "very robust and open" oversight and "make sure you monitor that damn thing", with the proponent paying, he said.

Resource Minister Anthony Roberts did not address whether the government would consider taking direct control of monitoring. His department, though, would work closely with key agencies and independent experts to assess the project's merits.

"Santos's Narrabri Gas Project is a strategic energy project for NSW and could supply up to half of the state's gas demand," Mr Roberts said.

Fairfax Media sought comment from Santos. A spokesman said the company was checking whether it was permitted to respond to EIS submissions so soon after the deadline closed on Monday.

Stuart Khan, an engineer at the University of NSW, said the EIS raised questions about how salt waste would be handled.

"Burying salt in a big hole in the ground is not a long-term sustainable solution," Professor Khan said. "It's simply transferring responsibility for managing the problem to future generations."

"Past failures appear not to have been drawn upon in developing the EIS," he said. "The issue of uranium migration in groundwater is an example... Any EIS should acknowledge that things don't always go precisely to plan and the environmental impacts of when things might go wrong should also be considered."

Mr Meppem said the EIS lacked detail on what Santos had found during their drilling and production on the pilot wells already built.

"I would have thought they would have provided actual samples just to allay fears," he said.

The council has not made a clear decision to support or oppose the CSG field. The venture did have the potential to generate more than 100 full-time jobs in the area and potentially bring cheaper gas that would support local industries, Mr Meppem said.