Volunteers who have done most of the clean-up work on the Fox River to date say they wouldn't still be there, let alone racing against the clock, if the government had acted sooner.
From this week a large contingent of Defence Force personnel and vehicles have been helping clear rubbish where a disused Fox River landfill split open in March - but Kay Palmer from Nelson was unsure why that took nearly four months.
"It was late. This whole thing happened late. It should have happened straight away but government didn't step in early," she said.
"We've got the numbers now but this should have happened months ago."
Westland resident Mike Bilodeau first organised the clean-up in March before it was taken over by DOC last month, with help from the Defence Force.
Off the back of his work on the Fox River, Mr Bilodeau is now in the Philippines, advising the Boracay Environment Foundation as they tackle crippling pollution on one of the world's most famous holiday islands.
He said the government definitely should have acted quicker to solve Fox Glacier's problems.
"It would have been cheaper and it would have been more effective. It would have been cleaned out, like this could have been cleaned up in five weeks, and they could learn from it and then use what they learn [from it] to deal with all the other landfills around the country," he said.
Other landfills near waterways, which Local Government New Zealand estimate there are 112 of, were his second concern.
Associate Minister for the Environment Eugenie Sage in April said that they would be investigated. However, Mr Bilodeau said not a lot has happened, and she should be dealing with them as a matter of national emergency.
"It's just really irresponsible, especially when you see the scale of it. And now everybody knows that there's landfills ... hundreds of them, around the country. They're ticking time bombs that are just waiting to open and destroy New Zealand's coastal environment."
Volunteer Warner Milne said he was also worried about whether enough was being down to protect other vulnerable seaside landfills.
"This should be a lesson to councils, to environmental boards, to governments to take a look - see if you can remember where you hid that [rubbish] because it's not really hidden, you know."
Ms Sage said with about 100 tonnes collected to date Operation Fox was making good progress - and she refuted that the Defence Force response came too late.
"I think people who make that comment don't appreciate that it's very easy to mobilise one person or few people who live locally, but when you're mobilising Defence Force personnel from around New Zealand and their equipment, that has to take a bit longer," she said.
"I am delighted that the Defence Force came and they sent their reconnaissance team, they worked out what resources were required, what logistics were needed, and now they've got people on the ground, really helping."
Landfills are the responsibility of councils, she said, but DOC had stepped in on this occasion after Westland District Council called for help.
As for other at-risk landfills, she said an expert panel were continuing to investigate them as part of wider climate adaptation work.
"Yes, there's significant liabilities there, but there's no silver bullet solution sitting on the shelf," she said.
"This is a legacy issue. We've all created the waste collectively. I'm working as Associate Minister for the Environment with ministry officials on a big program to reduce waste going to landfills, but that takes time for society and the economy to change."
Mr Bilodeau is continuing to work closely with Operation Fox, and said he was motivated to push for better environmental outcomes.
He said the government simply needed to stop downplaying the issues before it was too late.