A further complication has thrown a spanner in the works of ongoing attempts to expedite the removal of more than 10,000 tonnes of potentially toxic waste from Mataura's disused paper mill.
In 2018, New Zealand Aluminium Smelters and Rio Tinto agreed with local councils and the government to remove the ouvea premix - a waste byproduct of aluminium production at Tiwai Point - over six years.
Flooding and fire at the site this year prompted the Environmental Defence Society to launch court action against the smelter's owners.
The plan remains to get the waste out of the paper mill by Christmas.
Alternate Environment Judge Laurie Newhook, in a minute issued this afternoon, said the arrangements had not been finalised.
"I regret finality has not been reached yet, a further complication having arisen in what has been a very complex situation," Judge Newhook said.
"Having said that, constructive progress continues on all fronts for removal of the ouvea premix from Mataura to an industrial site. Finalisation of the several necessary contracts is closer, considerable progress having been made in the last week.
"Logistical arrangements for the removal activities are now in hand.
"The parties remain focussed on the urgency of the situation and are continuing to act constructively and with expedition. The aim remains to complete it by Christmas (possibly weather dependent), subject to the remaining issues being finalised urgently."
Judge Newhook did not expand on the complicating factors.
The waste came to be in Mataura after New Zealand Aluminium Smelters contracted Taha Asia Pacific to deal with the waste products of Tiwai Point's aluminium production.
Taha moved more than 10,000 tonnes of ouvea premix and other dross into the papermill without resource consent six years ago.
The company subsequently went into liquidation still owing a $2 million bond to the Gore District Council for a retroactive consent for the dross.