Nelson Mayor Nick Smith expects it will cost millions of dollars to treat contamination at one of the country's most popular beaches.
Testing has found sawdust and wood pieces dumped in the 1960s is polluting Tāhunanui Beach with toxins like arsenic.
Smith said it's a symptom of a different era where coastal areas were treated as wastelands.
"Frankly I think it was quite reckless to be putting sawdust, let alone treated wood waste, in a coastal environment."
The wood matter was hidden for many years but was exposed after erosion from various weather events, including the August 2022 storm. The main 80m area at the back beach has been fenced off with signs warning of the danger.
"The greatest health risk would be if children were playing in it... where they may ingest the saw dust and the contaminants," Smith said.
While there's been no reports of issues there's also a risk to dogs and shellfish, he said.
Next week council will be asked to approve $450,000 to start urgent erosion mitigation work but Smith expects it will cost much more to fix.
Nelson City councillor Campbell Rollo met with some locals and businesses this morning who were concerned by the news. The beach is very popular, particularly during the summer months.
"There's still plenty of beach... we have fenced off an area that is affected but there's still plenty of area to use."
Beachgoers 1News spoke to today were concerned about the contamination and the potential impact.
Daniel Mortimer walks his dog every day at the beach and said he enjoys the peace and quiet. He's been concerned about the erosion of the sand dunes for awhile and wrote to the council about it two years ago.
"I suggested that perhaps they might like to think about putting in some sort of sea defences or something like that."
He's worried parts of the beach are too far gone and concerned by the discovery of the contamination. "It's not a good look... because it's all just going out into the environment daily."
Nelson resident Caroline Ferguson said it was "frightening" as she often walked her dog there. "We see lots of children, they play there. They climb up and jump over and my dog follows them."
Heather Bell said it needs to be fixed quickly. "It's a bit concerning to know that there's toxins leeching and I'm hoping that will be remedied pretty soon."
There's a big job ahead with around 200 trucks worth of contaminated material needing to be removed.
Smith said plans were still being worked out to remediate the area and find a safe area to dispose of the material. He couldn't yet give a time frame on how long it would take.
SHARE ME