The Narrabri Gas Project has caused so much stress in the North West region one opponent had a heart attack after speaking against it, the Independent Planning Commission (IPC) has heard.
Kathryn Dolphin told Commissioners on the third day of the seven-day hearing another opponent she identified had been sent to Tamworth Hospital after speaking on Tuesday.
She said it was an example of the "stress that this is causing in our region."
Ms Dolphin was among 73 people slated to address the three Commissioners about the proposed $3.6 billion scheme on Wednesday.
The week-long hearings are the climax of a 20-year controversy over Santos' plans for gas development in and around the Pilliga forest. Attracting a record 404 registered speakers, they could be the final stage before Santos wins approval for the controversial mine.
Many speakers have told the Commission they have been campaigning against the project since Eastern Star Gas struck the fossil fuel in the region in 2000.
But on Wednesday several speakers told the IPC they were just as committed in their support for the proposed mines.
Narrabri resident Jack Campbell, who has worked for Santos since 2013, rejected concerns about the risk of accidents, which could potentially lead to contamination of groundwater.
He said he "used to resent the extreme measures" the company imposed on staff like him to ensure their safety.
Former Liberal MLC and Guyra resident Scot MacDonald criticised opponents of the proposed 850-well scheme as misrepresenting the facts around the industry.
Far from contributing to climate change, he said, the industry had helped the US reduce national carbon emissions to levels it had not seen since the 1990s.
"There's a million gas wells sunk into the continent up there with, as the studies show, no impact on ground water," he said.
"It's a safe industry, it's been conducting itself well for about the last 60-70 years."
He said the "only rational decision here is to proceed".
But for the third day in a row, dozens of farmers and average residents of the North West took turns condemning the project to the IPC as a threat to groundwater, Indigenous heritage and the climate of the planet.
Narrabri councillor Ron Campey said he had sold shares in Eastern Star Gas and left the project community consultative committee when he realised the former proponent "never tells the whole story".
He accused Santos of trying to buy the community with community benefit funds and other "trinkets", comparing their attitude to European colonisers who bought large parts of the US for beads.
"The project does not pass the pub test let alone the precautionary principle," he said.