Farmers fear a CSG project in northern NSW will have a devastating impact on agriculture in the region.

Farmer Alistair Donaldson is worried a CSG project in northern NSW will have a devastating impact on a forest, sacred sites and agriculture in the region.

“It’ll just turn this place into an absolute shithole,” he says of Santos’ coal seam gas (CGS) project in the Pilliga.

There are eight wells operating at the moment as part of the pilot phase but Mr Donaldson reckon’s it’s only the start, claiming about 6000 had been sunk through the Great Artesian Basin in Queensland.

“This is the Trojan Horse here, 850 wells,” the 51-year-old told AAP from the farm his family have been working on for 135 years.

“It’ll probably move to other areas of the scrub and the actual forest and the conservation areas and then in all directions.”

Since July, only 50mm of rain have fallen on Mr Donaldson’s property which relies on four bores for his cattle and crops.

Drilling through the Great Artesian Basin will make the already scarce water harder to access and less reliable, he says.

“Anyone out there … if they don’t have a decent underground water supply they’re literally finished, their business will effectively close down,” Mr Donaldson said.

“I have such a fear for the future of agriculture.”

With many of the younger locals “frying their brains and their livers” on the huge wages they’re paid to work in the resources sector, Mr Donaldson fears there will be “a lost generation” of farmers.

“It’s pretty hard to find anyone that’s coming back on the land.

“The average age in farming around here’s about 57, 58.”

Earlier on Monday, officers ordered all protesters to leave the Pilliga but Carmel Flint from Armidale locked herself to a truck to prevent it moving parts of a drill rig through the forest.

The 42-year-old freed herself on Monday afternoon and was arrested, protesters told AAP.

A Santos spokesman said the actions of some protesters on Monday put their lives at risk, along with the safety of Santos workers.

“Santos’ exploration and drilling program in the Pilliga has all of the relevant government approvals to allow us to carry out a program that is both safe for the community and safe for environment,” he told AAP.