Water bottling companies are getting our very best water for free — from deep, uncontaminated bores — while a large and growing number of us get nitrate-contaminated drinking water through municipal supplies
Opinion: Having spent half my life trying to highlight the decline of New Zealand’s freshwater quality, I’m appalled to find that people are now telling me they’re buying bottled water to protect their health.
This is the last thing I wanted. I hoped raising awareness would lead to safe water quality standards, supported by tough enforcement, not boosting the sales of companies that bottle our precious, but free, water in plastic.
Worried about the unintended outcome of driving bottled water sales, my co-researchers at the University of Otago medical school and I decided to check nitrate levels in bottled water.
Why nitrate? Nitrate contamination is a clear indicator of the harm intensive agriculture is doing to our waterways and evidence has been emerging of the threat nitrate in drinking water poses to human health.
This emerging science is summarised in our recent publication, which highlights the link between nitrate contamination and human health impacts, in particular bowel cancer and adverse birth outcomes. New Zealand has one of the highest rates of bowel cancer in the world.
Bottled v tap
The results of our analysis of 10 bottled water brands sold in supermarkets delivered good news and bad.
Of the products tested, we found only one contained nitrate concentrations near the cancer risk level observed in recent studies— above 3.87 mg/L nitrate, or 0.87 mg/L expressed as nitrate-nitrogen. The rest had very low concentrations – four so low as to be almost undetectable.
Unfortunately, for at least some of us, the stuff coming out of the tap provides more to worry out.
Based on previous research, we calculate more than a million New Zealanders are drinking tap water with nitrate concentrations higher than the highest concentration in our bottled water sample.
What all this reveals is that the (mostly international) water bottling companies are getting our very best water for free — water from deep, not yet contaminated bores — while a large and growing number of us get nitrate-contaminated drinking water through municipal supplies.
Although bottling companies pay a resource consent fee, they pay nothing for the water itself. The reason, as former prime minister John Key, among many other politicians, made clear: nobody owns water in New Zealand.
Despite the nobody-owns-water rhetoric, we let bottling companies sell it for millions of dollars. New Zealanders pay $140 million a year for bottled water no one owns, and another $24m worth is exported.
We must surely be seen by the international water bottling industry as a great business opportunity – a clean, green reputation, allegedly some of the cleanest water in the world, and a country where you can get water for free and sell it back to the citizens.
The nobody-owns-water assertion has long been questioned by Māori. In 2012, the New Zealand Māori Council went to the Waitangi Tribunal over water ownership. In 2019, the tribunal found there was an economic, proprietary dimension to Māori freshwater rights. It also found the Resource Management Act breached the treaty by failing to recognise these rights.
Protecting our water legacy
Clean, safe water is a prerequisite for life, but we’ve been squandering our healthy water legacy. The blame can be laid fairly and squarely on the Crown on two fronts — failing to settle water ownership issues and failing to protect freshwater.
Increasing nitrate concentrations in our rivers, lakes, estuaries and groundwater are now not only risking the health of our environment but also our own health.
We must learn from our mistakes and put in place limits on pollution that protect our water sources, and enforce these limits.
Research suggests the level of nitrate contamination in drinking water that gives an increased risk of cancer is very close to the level known to trigger a decline in ecosystem health.
The answer is in front of us: keeping nitrate-nitrogen levels below 1mg/L will protect ecosystems and our drinking water.
