Safeguards protecting water supplies from mining projects are inadequate and companies who conduct shonky monitoring should have their operations overhauled, the state's top scientist says.
Environment groups want mining activity suspended until the government implements recommendations from a report by NSW Chief Scientist Mary O'Kane, including beefed-up water monitoring, greater expert involvement and a new commission guarding water quality at arm's length from government.
Fears that coal seam gas mining will contaminate water and land with toxic chemicals has galvanised community opposition to the industry in NSW, constraining its development and putting pressure on the state government to act.
Santos' Pilliga operation, near Narrabri, was a focus of concern in March after it emerged a nearby aquifer had been contaminated with uranium at levels 20 times the safe drinking water guidelines.
Professor O'Kane, who is conducting a broader review into coal seam gas in NSW, was asked by the government to advise specifically on water monitoring. Her report included coal seam gas and other mining, and irrigation.
She recommended new water sensors in high-risk areas, such as vulnerable aquifers or creek beds, and better measurement of original water conditions before mining starts, known as baseline monitoring. The report noted such data is ''missing for many projects''.
Data from monitoring devices should be transferred quickly to a central database, which would be accessible by the public, and examined by experts.
A new independent body, possibly known as the NSW Water Resources Impacts Commission, should oversee the process, the report said.
It found that while some risks to water are reasonably managed, there were ''gaps'' in identifying risks and managing data ''that lead to inefficiencies, lack of trust and transparency''.
Without better co-ordination ''there is currently no assurance that impacts are being comprehensively detected'', especially when multiple mining projects were involved, the report said.
Professor O'Kane said some mining companies thoroughly assessed their effect on water but others were ''not as good'', and projects where monitoring was ''shonkier'' should be overhauled.
She said mining companies, not the public, should pick up the tab for improved monitoring – potentially adding to a project's costs.
A Lock the Gate Alliance spokesman, representing landholders and activists opposed to gas drilling, said a mining moratorium should be declared on coal and coal seam gas until modelling had improved, adding the report confirmed ''we don't know enough to be … confident about the impact on groundwater''.
Australian Petroleum Production and Exploration Association chief technical officer Rick Wilkinson said water monitoring changes should take into account ''all users of the Great Artesian Basin, not just the gas industry, which produces a tiny percentage … of water''.
A spokesman for Resources Minister Anthony Roberts said the government would respond to the report but ''has made it clear any CSG activity must be safe and environmentally sustainable''.