The government is considering taking Rio Tinto to court to get it to clean up hazardous waste from its Tiwai Point aluminium smelter.
Around 10,000 tonnes of ouvea premix is still sitting in a disused paper mill on the banks of the Mataura River.
The toxic waste came close to being swamped by flood waters last week which could have set off a highly dangerous cloud of ammonia gas.
The tough talk from Environment Minister, David Parker, follows claims the company reneged on a verbal agreement given just last week to remove the waste.
Sort Out The Dross action group spokesperson Cherie Chapman told RNZ Otago-Southland reporter Timothy Brown the company should take care of its waste, instead of palming off the problem on to the people of Southland.