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Nitrate levels

The reason nitrate concentrations are rising in springs and lowland streams in Canterbury referred to by Tim Chamberlain (From effluent drain to organic farm, May 27) is simply due to the large-scale intensive dairy farming that has been permitted.

The pasture-based grazing system used at present has no meaningful constraints on the quantity of nitrate released, and is, as predicted, leading to widespread nitrate pollution and environmental damage.

The recent study by Joy et al showed the average nitrate concentration in groundwater impacted by dairy farming will rise to a staggering 21.3mg NO3--N/L, far in excess of the maximum acceptable value of 11.3mg permitted in the New Zealand Drinking Water Standard.

This unsustainable farming is rendering our drinking water undrinkable. Christchurch will also lose its low-nitrate groundwater drinking water source.

A 99% reduction in nitrate released by current farming practices is needed to meet standards that will protect our freshwater environments for future generations. Industry needs to act, stop ignoring the science that shows these impacts, and rectify this unsustainable situation.

Dr Doug Rankin, Cracroft

Opinion | Letters

en-nz

2023-06-01T07:00:00.0000000Z

2023-06-01T07:00:00.0000000Z

https://fairfaxmedia.pressreader.com/article/281848647984617

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