Over the last decade there has been a lot of media coverage on Nitrogen limits for New Zealand water. I have made this diagram to explain all the numbers from the perspective of a water drinking Aucklander (which I am).
References (Nitrate nitrogen mg/L)
- 0.067 A stream in the Waitakere Ranges
- 0.6 Stream life is highly likely sick
- 0.44 The lower Waikato River (five year median)
- 0.87 Increases colorectal cancer in humans
- 1.0 Bottom line opposed by farming industry in 2020
- 2.4 Makes 5% of stream life sick in lab experiments
- 5 Increases premature births in humans
- 6.9 Makes 20% of stream life sick in lab experiments
- 11.3 WHO limit to stop blue baby syndrome
- 11.3 NZ drinking water safe standard