A NSW coal mine extension was approved despite evidence suggesting it would lead to higher salinity levels than if no mining occurred, the NSW Land and Environment Court has heard.

Conservation group 4nature is trying to prove the discharge from the Springvale coal mine, near Lithgow, is polluting water in contravention of quality laws. Barrister Richard Lancaster SC told the court that tests before approval indicated the project would lead to an “extravagant increase” in salinity at the discharge point…