Anti-glyphosate protestor outside Auckland's Town Hall (Photo: Sarah Smuts-Kennedy)

Hot water or chemicals? The controversy over weed killer in Auckland’s streets

On Thursday, Auckland Council voted on whether to standardise how weeds are managed across the region. Here’s what happened and why the issue has proven so controversial. 

What’s all this then?

The Auckland Council Environment Committee recently debated its Project Streetscapes proposal which would seek to standardise the methods of managing weeds throughout Auckland’s road corridors. The proposal argued that because different areas of the city use different methods of weed management which range in cost, toxicity and carbon emissions, a standardised approach was needed to make it fair across the region and keep it within the budget.

However, because it would shake up the way Auckland uses glyphosate, the proposal was met with vocal opponents who raised concerns about the impact on the health of Aucklanders and the environment.

But what exactly is being proposed?

Auckland Council argues that standardising the approach and using a mix of low-cost glyphosate spray and plant-based herbicide would help reduce costs – and average out use of glyphosate – across the city.

At the moment, local boards are able to use different methods of weed-killing according to their budget. For example, the North Shore predominantly uses thermal methods or steam treatment which, while perceived to be safer, are ostensibly more carbon and water-intensive. Manukau and Waitākere, on the other hand, mainly use low-cost glyphosate to kill weeds.

This apparently means that some areas – like the North Shore – get a bigger share of the budget to afford its more expensive, but less toxic, methods.

“This means ratepayers in some areas of Auckland effectively subsidise the more expensive thermal methods used in other areas,” Auckland Council said in a statement.

“The recommended approach is fairer and provides for local choice. Under this proposal, regional budgets will be distributed fairly across all local boards by funding the recommended method of combined plant-based herbicide and glyphosate.”

The council’s preference for a combination of synthetic and plant-based herbicide was based on the following costs per kilometre:

  • Glyphosate: $575 per km
  • Combination of glyphosate and plant-based herbicide : $1,050 per km
  • Plant based fertiliser: $1,500 per km
  • Thermal methods: $3,200 per km

The proposal estimates that glyphosate use would be reduced by 3,000litres per year, while the use of potable water in thermal methods along with greenhouse gas emissions from heating the water would also drop.

But what exactly is glyphosate and why is it so controversial?

A synthetic herbicide, glyphosate attracted controversy in 2015 when the World Health Organisation – from which much of the world takes its queue these days – deemed it a “probable carcinogen”. Some countries, including Germany, have moved to ban its use. However, the WHO’s statement was subsequently disputed by parts of the scientific community which said there was limited evidence to support the claim that glyphosate would cause cancer in humans.

This debate over its safety has been further coloured by numerous legal cases brought against giant glyphosate-producing companies from farmers who developed cancer after using products such as Roundup.

Roundup products (Photo: RNZ)

However, New Zealand’s authorities are instead basing their position on a body of scientific discussion that suggests glyphosate is safe if used properly. Auckland Council says its proposal was guided by the New Zealand Environmental Protection Authority (EPA), which has approved glyphosate-containing substances.

“We are aware that some reports linking glyphosate to health impacts are causing concern. We are in alignment with the vast majority of regulatory bodies around the world – including in the European Union, United States, Australia and Canada – which agree that glyphosate is unlikely to cause cancer,” the EPA said in 2019.

The proposal suggests that the glyphosate product used does not contain the particularly harmful additives found in the more controversial varieties and therefore does not pose much of a health risk if used properly.

The other concern, of course, is the impact on the environment, particularly on pollinators like bees. Numerous studies have investigated the effect of synthetic herbicides on honeybees, which may include impeding the growth of bee larvae, diminishing bees’ navigational skills, altering their foraging behaviour, or even disrupting their gut microorganisms, known as the microbiome.

Who is opposing the proposal?

From local businesses to organisations, there are a number of vocal opponents to the proposals, some of whom staged a protest outside the Auckland Town Hall on the morning of the vote.

One opponent present at the committee was Kaipātiki Local Board chairman John Gillon. He said his board’s road corridors had been relatively free from chemicals for decades because of lengthy campaigns among local residents and organisations, and the proposal would stretch its budget, forcing it to use more glyphosate. At the moment, it was only used sparingly for spot treatment.

He said the proposal would override the independent decision making of local boards and force ratepayers to accept a lower standard of service.

“We are having the rug pulled out from under us,” he said at the committee.

According to the NZ Herald, the proposal would mean “North Shore boards wanting to continue with steam and hot water would pay an extra $1,293 per kilometre of footpath berm sprayed.”

Anti-glyphosate protestors outside Auckland’s Town Hall (Photo: Sarah Smuts-Kennedy)

Another opponent is Sarah Smuts-Kennedy from urban environmental protection organisation For the Love of Bees. She argues that not only does the proposal underestimate the harm of glyphosate, but it also doesn’t factor in the topical harm of the plant-based herbicide – a long chain fatty acid that inhibits the growth of the weed.

“What was frustrating is that actually there are alternative strategies, which include thermal and mechanical.”

Smuts-Kennedy said the proposals do not correlate with the Auckland Council’s commitment to mitigate climate change and to protect biodiversity and human health.

“The proposal that came forward absolutely didn’t meet any of those KPIs. It was really important that we got something into this long term plan that actually removes these really toxic things that we no longer need in our ecosystem.”

“That’s not to say that there aren’t going to be instances where a little bit of spot spraying of glyphosate is applicable in certain areas.”

What was the outcome of the committee?

Two major issues characterised the meeting: the use of glyphosate vs. the equity of funding across the region. Auckland Mayor Phil Goff acknowledged that it was a controversial issue and that “safety was the most important issue in this debate”. However, he expressed his view that despite concerns, if New Zealand’s EPA didn’t think glyphosate was harmful if used properly, then there was nothing to worry about.

“They are science-driven,” said Goff. “You can guarantee that they did their work.” He also said the council did not have the budget to completely phase out glyphosate in favour of thermal or mechanical methods.

Ultimately, the final outcome of the meeting was a unanimous vote to standardise budgets – but not weed killing methodology – across the region. Based on the initial proposal, there would be a massive reduction in glyphosate use in Waitākere and Manukau, and an increase in glyphosate use on the North Shore.

However, councillors disputed the methodology costings in the original proposal and, after amendments were made at the committee, it was decided local boards would still have the capacity to seek out alternative methods of thermal and mechanical weed management within their budget. This would include using non-potable or greywater for thermal weed killing, or glyphosate spot spraying in certain cases.

Councillor Wayne Walker, who said he advocated for Germany’s approach to ban glyphosate completely, said today was a fair outcome. “I think it was probably the best decision that we were going to get,” he said.

“So what we do have now is a [standardised] budget. We still don’t know what the precise amount of budget is and that’s something that we need to get a handle on. But I’m quite confident that the budget that is available for weed management across the region is going to be sufficient, based on competitive pricing, to allow methods like hot water to be used everywhere.”

And what if Aucklanders want to opt out?

In any case, Aucklanders don’t need to have herbicides sprayed outside their property if they don’t want to.

Auckland Council has a no-spray register, which anyone can join to opt-out of weed control with agrichemicals on the berm or park boundary of their properties. People who join this register will not have the front of their properties sprayed with herbicide as long as they adequately maintain the area themselves.




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