Government must ban synthetic fertilisers | The Jackal

30 Jul 2021

Government must ban synthetic fertilisers

ECan’s science director Dr Tim Davie
Now I hate to be the bearer of bad news, but the use of synthetic fertilisers on farms is polluting our water supplies. In fact the problem has become so bad that in some areas high levels of nitrates have made the water carcinogenic to drink.

But what’s even worse is that the regional councils tasked with keeping people safe by monitoring the levels of pollution in our water are fudging the stats in order to try and hide the true extent of the problem.

They are in effect placing the profits from intensive farming ahead of the health and wellbeing of the general population, which is of course an entirely unacceptable thing for duly elected officials to do.


Yesterday, Newsroom reported:


‘Tricky’ council masks nitrate effect, Mike Joy says

Environment Canterbury is ignoring its own data to cover-up nitrate pollution, freshwater ecologist Dr Mike Joy says. It’s a claim the regional council rejects.

Last Friday, ECan, as it’s known, released its annual groundwater quality survey, which showed that between 2011 and 2020, 47 percent of wells (118) had either likely increasing or very likely increasing nitrate-nitrogen concentrations.

This is important because high nitrate in groundwater can pose health risks to people drinking it. When it flows through to waterways and lakes it can kill fish, and cause excessive weed growth and algal blooms.


Intensive farming is one of the main reasons why New Zealand has such polluted waterways. It’s also why we have such high levels of colorectal cancer, because nitrate pollution has been shown to be carcinogenic to human beings.

So you can understand why certain people, including councils that are predominated by old white farmers, would want to downplay or cover-up this kind of information.


Some ECan well records stretch back to 1989 but the data are not used. In that way, Joy says, the “snapshot” survey uses “tricky stats”.

When he ran the numbers on ECan’s groundwater data two years ago, he found the trends for degraded wells were more pronounced than were being reported, at about two-thirds.

“They’re doing everything they can to gild the lily,” Joy says. “And if they were to stop that, and actually use the full-time record, and not try to do this ‘just 10 years’ bit, then they would actually get some truth around what’s happening.”

(The ECan report also notes its trends differ from those on the Land, Air, Water Aotearoa website because it uses different time periods and sampling frequencies. “It’s the same data,” Joy says with bewilderment. “LAWA isn’t a separate body that collects its own data, it’s a housing point for regional council data.”)


The Canterbury Regional Council can therefore not be trusted to factually report on the true extent of the problem, and like most councils, have been caught using selective data in order to try and hide what is a major environmental and health catastrophe for New Zealand.

This isn’t just a problem in terms of polluted groundwater either; it’s a legal liability issue as well. Because without accurate data showing exactly how polluted the water has become, proving that synthetic fertilisers are the cause of people’s ill health is even more difficult.


A Danish study published in the International Journal of Cancer three years ago, which followed 2.7 million people over 23 years, found increased risk of colorectal cancer for those exposed to high nitrate concentrations.

New Zealand has one of the highest rates of bowel cancer in the world.

Environmental groups in this country are using the Danish study to call for a 1 milligram per litre limit for nitrate in waterways. (The study, which suggests a threshold of 0.87mg/L for nitrate nitrogen, found a statistically significant increased risk above 3.87mg/L.)

The World Health Organisation (WHO) drinking water standard is 11.3mg/L, adopted as this country’s maximum acceptable value, after which bottle-fed babies are at an increased risk of blue baby syndrome.


In my opinion, the New Zealand Government should listen to the latest science on this issue and adopt a 0.87mg/L nitrate limit. This will of course render most of our aquifers unusable for tap water. But that’s a better price to pay than having numerous people suffering from ill health from pollution that is costing millions if not billions of taxpayer dollars each year to treat.

Clearly clean drinking water should be a fundamental human right and farmers should be the ones to pay for taking it away. But instead of realising that they’re legally liable for polluting our water and causing people cancer, the farmers are continuing to use synthetic fertilisers like there's no tomorrow.


Greenpeace has recently run nitrate testing in various parts of rural Canterbury, at which 450 samples have been tested, and in Southland. Abel, who has attended the testing, says people shouldn’t be left wondering.

“People trust the health limit is 11.3mg/L, that if they’re under that limit then, so far as the official word is, they’re avoiding health risk. The emerging science tells us something very different to that.”

ECan says it contacted the owners of all wells with concentrations over 11.3mg/L. (The highest recorded concentration was 22mg/L.) Most are not used for drinking water, groundwater science manager Carl Hanson said last week. Some owners have installed filters, others have replace their wells.

“The authorities need to stop worrying about covering their arses and think about their first obligation,” Abel says, “which is to make sure that the public are properly informed and advised of the potential health risks.”

He adds: “They need to face up to the fact that what we’ve done with 30 years of a near seven-fold increase in synthetic nitrogen fertiliser use and a doubling of the dairy herd, is we are in the process of turning people’s drinking water carcinogenic.”


The aquifers will remain polluted though, perhaps for thousands if not millions of years. That’s why it’s imperative that synthetic fertilisers aren’t allowed to pollute the few remaining untainted groundwater supplies we have left in New Zealand, or continue to make the situation worse in aquifers that have already been polluted.

The only way to effectively do that is for the Government to place a total ban on the use of synthetic fertilisers. Because without a ban, the farmers and councils will assuredly continue to place profits ahead of people's health and wellbeing, which is something that must not be allowed to continue indefinitely.