Coal seam gas extraction in water catchment areas is a bad "joke" that New South Wales has the chance to end forever, the Liberal Member for Heathcote has said.
Lee Evans, who has been outspoken on coal seam gas issues, has written to Premier Mike Baird making clear his view.
"My seat contains the water filtering system for 4 million residents of New South Wales," Mr Evans said.
"My job is to protect it ... it's now time to draw a line in the sand and ban forever any other industries going into the water catchment."
His comments came after the long-awaited Chief Scientist's report into coal seam gas, which said risks to human health and the environment can be "managed" with developing science, but "unintended consequences" from accidents, human error and natural disasters were inevitable.
An earlier part of Professor Mary O'Kane's review said there was not a "complete" understanding of the impacts of CSG in catchments. But the final report has not specifically called for a ban in catchment areas.
Mr Evans said the risk was not acceptable.
"There is no 'oops' in this argument," he said.
"If at some stage there is a problem, that's our drinking water."
The report was seized on by industry boosters as giving the "green light" to CSG.
The Australian Petroleum Production and Exploration Association said the report showed the CSG industry can be safely managed.
"APPEA welcomes the Chief Scientist's observations that the natural gas industry is mature and well equipped to manage extraction and related technologies through its high engineering standards and level of professionalism," it said in a statement.
Environment groups said the review showed the industry needed to be banned altogether.
Professor O'Kane wrote that CSG has problems with trust and fear in the community, but is not more dangerous than other oil or mining operations.
"The review examined this issue in detail and concluded that while the CSG industry has several aspects that need careful attention, as do almost all industries, it is not significantly more likely to be more damaging or dangerous than other extractive industries," she wrote.
Mr Evans said the report worked within its terms of reference, which he said were "quite narrow".
"It was to see if we can co-exist with water catchments, and she's done a job erring ... on the side of caution.
"I believe it should be a bit more than caution - I believe we should not be dallying with our future water resources.
"Other parts of New South Wales are quite good for CSG exploration, but not special areas of water catchment, put a line under it."