Ōtautahi Christchurch: the water city? Video / Frank Film
A test carried out by Greenpeace measuring nitrate levels in Ashburton’s drinking water has, once again, concerned the environmental campaigners.
“Unacceptably high” levels of nitrate have been found in the region’s water, the tests reveal.
The organisation carried out a similar test in October 2021 which showed a similar issue,revealing the water was loaded with nitrate contamination.
Elevated measurements of the chemical are due to the large increase in the use of synthetic nitrogen fertiliser in the region. Photo / Mark Mitchell
Elevated measurements of the chemical are due to the large increase in the use of synthetic nitrogen fertiliser in the region, a 700 per cent increase to be exact.
Its heavy use is because of a ten-fold growth in dairy cows across Canterbury over the past 30 years.
The maximum acceptable amount of nitrate in New Zealand drinking water is 11.3 mg/L, set in the 1950s. However, Danish studies have revealed even at 1mg/L that the risk of bowel cancer increases.
Of the 107 tests carried out on Saturday in Ashburton, 77 per cent showed at least a 1mg/L reading, while a concerning 11 per cent of tests showed a nitrate level exceeding the national standard.
Greenpeace Aotearoa’s lead campaigner, Christine Rose, said that big dairies in the region are maximising profit whilst polluting drinking water with nitrates and putting communities at risk.
“Clean, safe drinking water is a basic human right,” she said.
“Unacceptably high” levels of nitrate has been found in the region’s water according to the tests. Photo / File
“No one should have to wonder if the water from their kitchen tap is unsafe to drink, but for many people around Ashburton - and in other rural communities - that is their reality.”
Rose called out the Government to decide whether it will “protect drinking water” or “allow big dairy corporations...to continue polluting water with nitrate for the sake of maximising profit”.
She said the levels were particularly concerning in autumn, as the highest nitrate readings will usually come in spring.
“What we’re seeing here in Ashburton is totally unacceptable,” said Rose.
“The Government needs to take urgent action to address nitrate contamination at the source, to protect the health of rural communities”
Environment Canterbury (ECan) recognised the nitrate issue within Ashburton’s drinking water, however its Director of Science, Dr Tim Davie believes Greenpeace has misrepresented its data.
Davie said Greenpeace had presented its sample results by using statistics based on a single Danish study, rather than New Zealand’s Drinking Water Standards, set by the Ministry of Health and Taumata Arowai.
Environment Canterbury officials believe that Greenpeace has misrepresented its data. Photo / Christchurch Star
“For drinking water, the [Drinking Water Standards] set a Maximum Acceptable Value of 50 milligrams per litre for nitrate, which is equivalent to 11.3 [mg/L] nitrate-nitrogen,” said Davie.
“This is based on the World Health Organisation standard. A 2018 review of the science behind the WHO standard, which included the Danish study, concluded there was not enough evidence to change those limits.”
Davie also pointed out the samples were taken mostly from private wells on rural properties and not the main Ashburton town drinking water supply.
In 2018, ECan made amendments to the Canterbury Land and Water Regional Plan, which required a 45 per cent reduction in nitrogen losses in large parts of the Ashburton District.
According to Davie, the only way to address the issue is “through a reduction in nitrate leached into groundwater”, something ECan is currently doing with help from the community.
Farmers are able to reduce the possibility of nitrate leaching by matching how much fertiliser they place on the ground with the amount of crop planted.
Mid Canterbury’s president of Federated Farmers, David Acland agreed that the community was doing what it could to ensure progress in reducing nitrate is swift.
