Kirwee nitrate testing campaign results

May, 2021

During the South Island Agricultural Field Days, 24-26 March, HydroMetrics exhibited and set up a nitrate water testing station on the Kirwee grounds. This event attracted many locals who wished to test their rural water supply.

66 private well water samples were submitted by local Cantabrians and measured for nitrates. The water samples came from areas such as West Melton, Burnham, Rolleston, Darfield, Springston, Leeston, Southbridge and Ashburton. Of the water samples submitted, 48 people kindly agreed to allow us to share their results anonymously so others in the region could understand the potential issues.

Below are the results from our public testing day:

SIAFD nitrate graph

Looking at the graph, HydroMetrics recorded 1 water sample that were highly elevated in nitrates; double the recommended nitrate limit set by the World Health Organisation (WHO) of 11.3 mg/L Nitrate Nitrogen.

The orange line, the WHO Maximum Allowable Value (MAV), shows a total of 5 samples were above the 11.3 mg/L Nitrate Nitrogen limit.

Furthermore, 21 samples (equivalent to 42.9% of the submitted samples) were recording more than 50% of MAV (thick grey line on the graph).

11.3 mg/L Nitrate Nitrogen (NO3-N) limit is recommended by the WHO and this limit is currently adopted by the New Zealand Government.

HydroMetrics designs and manufactures real-time groundwater monitoring sensors for environmental, agricultural and industrial uses. The business is a division of Lincoln Agritech Ltd, a research and development company owned by Lincoln University, New Zealand.

If you have any questions regarding this study, email us at or phone us on +64 3 325 3700.

For those that wish to continue monitoring their private wells via spot sampling, we recommend submitting your water samples to Hill Laboratories ( for testing.