WA Premier Mark McGowan warned Alcoa to lift its game or face curtailed mining, but his successor Roger Cook slashed water supply protections after a possibly empty threat from the US miner.
Canadian firm Vermilion judged the chance of the December spill as "rare" - the same probability it claims for seven planned exploration wells that could affect anywhere along the Pilbara coast.
Plans by Santos, which negligently caused an oil spill off WA four years ago, to drill seven exploration wells off the Pilbara coast have drawn fire from an environmental group.
