In their submissions, agencies such as the NSW Environmental Protection Agency and DPI Water said they did not find "critical" issues to recommend the project not succeed. They do, however, detail gaps in many aspects of the project's environmental impact statement (EIS) that hinder their ability to assess those effects.

For instance, Santos presented insufficient data for the EPA to evaluate the impact on water levels of the proposed 850 CSG wells to be drilled in Stage One, the agency said.

DPI Water assessed the confidence of the groundwater model used to be "Class 1" because the groundwater pressure and level data for key formations "is limited". Such class of models "have a high level of inaccuracy which results in uncertainty of modelled impacts", DPI said in its submission.

Water worries head the concerns of local farmers such as Sarah Ciesiolka, whose family runs a farm producing 50 million potatoes a year just six kilometres to the north of the project. Her 945-hectare farm also produces 1000 tonnes of peanuts annually, among other crops.

"If the water is compromised in any way through drawdown or contamination, we're sitting ducks," Ms Ciesiolka said. "We don't have a business if we don't have access to that pristine water."

Those concerns were outlined in a submission on Santos' EIS by the Ciesiolkas. The fifth-generation farmers, who have been in the Narrabri region since the early 1970s, say they can't insure against potential environment impacts on their operation for the past three years and nor can their neighbours.

"This is the trojan horse to get things started," Ms Ciesiolka said of stage one, noting Santos has identified seven gasfields in its exploration licence for the region. "From here they are going to spread out across our highly productive and highly valued agricultural land."

A spokesman for the project said: "Santos welcomes the opportunity for the community to have their say on the Narrabri Gas Project and the EIS and we recognise the important role this part of the assessment process will play in ensuring a robust and thorough assessment.

"Santos will liaise with the Department of Planning and Environment and prepare a response to the submissions in due course."

Fugitive emissions

The EPA also found gaps in the company's air-quality assessments.

"The potential fugitive emissions, including emission of [volatile organic compounds], air toxics and odorous substances, from the proposed operations have not been adequately identified and quantified," the agency said.

As a result, there was insufficient data to support the proponent's view that the emissions "will have no direct impact", the EPA said.

Georgina Woods, NSW coordinator of Lock The Gate, noted other gaps, such as DPI Water finding Santos holds only 600 megalitres worth of licences in the Gunnedah Oxley Basin a year while their basic modelling found extraction rates could soar to almost ten times that amount to 5922 ML annually in years 2-4.

The Office of Environment and Heritage's submission also found Santos' submission does not meet the standard of the Framework for Biodiversity Assessment, which is supposed to apply.

"They have not put in sufficient surveys to cover the very large area that will be affected," Ms Woods said, noting OEH plans to ask Santos to undertake more thorough studies of the impacts for several species, including koalas, spotted-tail quoll and the rufous bettong.

"They are cutting corners in their surveys for threatened species and wildlife in the Pilliga, which everyone knows is an extraordinarily important, large temperate woodland."