All of the 10,000 tonnes of aluminium dross by-product stored in Mataura's old paper mill site next to the Mataura River has been removed.
Environment Minister David Parker welcomed the news that the last bags of dross were moved from Mataura last Wednesday to be stored in watertight shipping containers at New Zealand Aluminium Smelters' Tiwai Point.
"The safe removal means Mataura residents no longer need to worry about the risk from the material, which gives off ammonia gas if it gets wet.
"I'm glad that the dross has now gone from Mataura and local residents don't need to worry any longer. The safe removal will protect the wellbeing of Southland's people and its waterways.
"Now that the Mataura site has been cleaned up, the focus will move to the removal of material from other known sites in Southland," David Parker said.
David Parker thanked the organisations that contributed to the successful remediation.
"It has taken a long time to get to this point and I'd like to thank everyone involved including the Gore District Council, Environment Southland, the Environmental Defence Society, Ngāi Tahu, New Zealand Aluminium Smelter and Inalco Processing Ltd."
Rio Tinto has agreed to pay the $6 million cleanup bill.