Green Party supports call for World Health Organisation Nitrate Review

Posted at November 03, 2026 12:34 PM by Lan Pham

The Green Party supports the call from experts urging the World Health Organisation to update drinking water guidelines for nitrate and says this shows the need to protect human health from the growing threat of contamination from intensive farming.

A letter to the WHO, signed by over 80 leading global health, environment, and food advocacy organisations including local organisation OraTaiao (Aotearoa NZ Climate & Health Council) argues that current guidelines for nitrate are outdated and risk exposing the public to a range of adverse health risks, including bowel cancer, preterm birth, and birth defects.

"It’s clear that agricultural intensification is linked with increased exposure to nitrates in New Zealand’s drinking water, and it’s time for the limit to be reviewed” says Lan Pham, Green Party spokesperson for the Environment. 

"Excessive nitrate contamination has forced communities in Gore, Waimate, Selwyn, and Ashburton to fork out millions, alongside a number of schools spending tens of thousands of dollars on upgrading water treatment or finding new drinking water supplies." 

"In total, twenty-one schools across Otago, Canterbury, Manawatū, Hawkes Bay, Bay of Plenty, and Waikato have exceeded half of the Maximum Acceptable Value for nitrate in their water supplies.”

"That's not to mention up to 800,000 people who are estimated to be on drinking water supplies with potentially harmful levels of nitrate."

"Midwives in nitrate contaminated areas of Canterbury advise pregnant women not to drink their water. It is unacceptable this is happening in New Zealand."

"It is clear that nitrate is a national issue that poses serious risk to our communities. What we’re seeing with this letter to WHO is that there is now a global push to take action."

“Under Luxon’s Government we’ve seen freshwater and environmental protections weakened significantly, and the health of our rivers, lakes and aquifers decline.”

"The Green Party has a plan to protect the health of New Zealanders and our environment from nitrate contamination with our Drink, Swim, Fish policy." 

"The Green Party would lower the allowable nitrate limit in drinking water, lower the cap towards a phase out of synthetic nitrogen fertiliser, reduce dairy cow numbers, and support farmers to transition to more sustainable practices. The Greens will also change how drinking water quality data is reported so everyone can understand exactly what is coming out of their tap.”

“Everyone should have confidence that the standards protecting their tap water are fit for purpose. Having a standard that was set in 1958 and is showing evidence of harm isn't good enough in Aotearoa” says Lan Pham.