A parliamentary inquiry into the coal seam gas industry in NSW has found two of 16 recommendations for the controversial industry have been implemented, more than five years after the Chief Scientist made them.

Omissions included the failure of the Liberal-Nationals government to recover funds from industry to pay for its own regulation. Taxpayers had so far had to pay some $20 million, with the tab rising at the rate of $3.75 million a year, the inquiry's final report found.

Part of Santos's Narrabri coal seam gas project in the Pilliga State Forest of north-western NSW. Credit:Dean Sewell

Similarly, the government had failed to implement the Chief Scientist's recommendation that it consider introducing a "robust and comprehensive policy of appropriate insurance and environmental risk coverage".

"This is unacceptable," Georgina Woods, a campaigner for Lock the Gate, said. "It means landholders and the public more broadly have to bear the risk if something goes wrong."