One major gas supplier says ongoing protests mean they will charge more when the gas is flowing.

Australian mining firm Santos Ltd says protests over exploration in the Pilliga forest are costing up to $100,000 a day. The company says those costs will be passed onto consumers when its new CSG wells come online.

Several people have been arrested and crowd numbers are growing at protest sites in NSW’s Pilliga forest, where activists, conservationists, local residents and farmers have been making their opposition known.

The chief of Santos’ east coast arm, James Baulderstone, said there are about twenty permanent protestors set up in the forest to interrupt efforts to get at the gas.

“These people are diving under trucks, bolting themselves on, refusing to comply with police, they are taking the law into their own hands... that's where these groups overstep the line,” Mr Baulderstone said.

The executive says the show of people power only makes his gas more expensive.

“What it does is adds to the cost base. At a loss of $100,000 a day, when I sell the gas in three years the consumer will have to pay for a portion of that,” he told News Corp reporters.

Santos has permission to drill fifteen exploration wells in the Pilliga State forest, as part of an agreement to supply 25 per cent of NSW's short-term gas needs and supply up to 50 per cent later on.

Protestors say Santos has no legitimate social licence to operate, and they believe the company has forced itself upon their natural resources.

Residents say vital underground supplies are at risk.

“The water under the Pilliga, recharged in this forest, supports the entire region, and that’s why people have come from across the region to risk arrest to stop Santos from drilling into the Pilliga again,” local farmer Kim Revell said.

The chief of Santos thinks the company and the protestors need to find some “middle ground... which isn't doing everything everywhere, but neither is shut the gate and do nothing,” he said.