Recent study confirms Aotearoa’s drinking water is being poisoned by intensive farming

NZ Herald Science and Environmental Reporter, Jamie Morton

A recent study confirms what most of us already know – that Aotearoa/New Zealand’s drinking water is being poisoned by intensive farming – dairy and cropping – from its by-products of urine and urea-based fertiliser.

Read the full story by NZ Herald reporter Jamie Morton ‘Nitrate pollution: Concerning levels in 60% of freshwater sources’.

The maximum safe level of nitrate-nitrogen in Aotearoa/New Zealand is 11.3 mg/L; however studies show levels of less than 1.0 mg/L are linked to high rates of colorectal (bowel) cancer and biodiversity decay.

This GNS Science study found nitrate-nitrogen concentrations of above 0.9 mg/L in 60% of freshwater samples analysed, and that groundwater (aquifers) was much more contaminated than surface water (rivers). This is a concern because once groundwater becomes contaminated it can take decades for nitrate-nitrogen levels to decline.

The issue here is that Kiwis are dying from unregulated intensive farming practices.

The answer is land use change.

The barrier to achieving change is successive governments of whatever colour too fearful to confront the powerful farming lobby.

The solution lies at the ballot box. 2023 is election year - make this an election issue, ask your local candidates where they stand on intensive dairying and nitrate poisoning?

Note: Pollution levels in this story are expressed as both nitrates and nitrate-nitrogen

• Nitrate (naturally occurring) comes from the decay of organic material and animal plant waste (defecation);

• The level of nitrogen within a nitrate molecule is just under 25%, and is referred to as nitrate-nitrogen;

• Aotearoa/New Zealand has set a Maximum Acceptable Value (MAV) level of nitrogen in drinking water of 11.3 mg/L (i.e. this is the amount of nitrogen contained within a 50 mg/L nitrate sample);

• Many scientists argue that the 11.3 mg/L level is way too high, as studies show levels of less than 1.0 mg/L are linked to high rates of colorectal (bowel) cancer;

• The primary source of nitrate-nitrogen in groundwater comes from intensive farming, both dairy and cropping from urine and urea-based fertilisers.

Note: Naturally occurring levels of nitrate-nitrogen have been measured at between

0.25 mg/L – 3.5 mg/L.

For more detail about the composition, causes and effects of nitrate check out the Land, Air, Water Aotearoa (LAWA) link here.