Public faith in the $3 billion coal seam gas field proposed by Santos is unlikely without independent monitoring of its environmental impacts, according to the head of planning at Narrabri Shire Council.

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.