While the river spreading the rubbish from the closed Fox Glacier Township Landfill has been successfully diverted, the massive clean-up effort is far from over. Westland District Council says rubbish has been sighted as far north as Ōkārito and south to Martins Bay in Fiordland.
Volunteer response coordinator Mike Bilodeau has been on the ground at the clean-up site, coordinating volunteers - who were having to avoid poisonous chemicals as they retrieve piles of rubbish.
"We've found some herbicide jugs with liquid in there - we don't know what's inside of it obviously, plastic containers that say toxic on them that have liquid inside, roofing panels with asbestos and some oil containers," Mr Bilodeau said.
"We instruct our volunteers to just leave them."
Mr Bilodeau has been helping to get volunteers onto helicopters to reach remote parts of the coastline, as well as picking up waste on beaches to the north of the Waiho River.
He said a dead seal had been found on the coastline, but it was too soon to tell whether the rubbish spill played a role in its death.
"Sometimes you think you've cleared an area and then you'll lift up a rock or you'll lift up a log, and there's way more underneath it.
"I've also noticed areas I've cleared, I've gone back the next day and it's just as bad, if not worse."
Conservation Minister Eugenie Sage and West Coast MP Damian O'Connor met groups helping to clean up the coast on Friday to discuss the next steps. So far no funding has been pledged.
Volunteer Andrew Elphick was preparing to be dropped into remote Westland on Saturday morning.
He said he was devastated that the rubbish was entering the habitat of the Hector Dolphins, endangered penguins and other creatures making the West Coast their home.
"Those will start to get infected from this plastic being introduced.
"The pristine place that we have on the West Coast and our best efforts to stop this in recent years, don't stop this little ticking time bomb that we have in these dumps," Mr Elphick said.
He said he remembered joining hundreds of other people to clean up about 300m of coastline last year after gale force winds from cyclone Fehi exposed decades of buried rubbish in Greymouth.
They were similar size dumps, but the scale of spread was vastly different - especially if the rubbish had reached Fiordland, Mr Elphick said.
Forest & Bird conservation group manager Jen Miller said the extensive spread of the rubbish would cost a lot of time and resources to clean up.
"Our concern is this is likely to happen to other landfills that are similarly exposed. The situation will get worse because the predictions around climate change are likely to get worse," Ms Miller said.
"We really need to take this very seriously. This has to serve as a wake-up call."
More than a hundred disused rubbish dumps around the country were vulnerable, she said.
Westland District mayor Bruce Smith said the majority of the rubbish was in the Fox River and beaches close to the river mouth.
The council had contracted EnviroNZ to manage the clean up of the Fox River bed while supported by the Department of Conservation, both the regional and district councils and many volunteers, he said.
Mike Bilodeau said there were lessons to be learnt by all New Zealanders from the devastating spread.
"Looking at this isolated incident, we need to ... all take a look at ourselves and the choices we're making when we're supporting the single-use plastic industry because when you're down there on the ground, it's heartbreaking. The things that you're picking up are things we use every single day."
Efforts to remove the rubbish are expected to ramp up after the weekend.
