Palmerston North's water supply has narrowly escaped serious contamination after a milk tanker overturned on a goat track.
The driver - who dairy company Fonterra said was not seriously hurt - died the same day.
Fonterra said his death and the accident in the Turitea Valley, both on Sunday, were unrelated.
It appeared the driver was unfamiliar with the area and had taken a wrong turn, the company said. It was investigating the accident, in which 9000 litres of milk spilled in the valley.
Jacqui Ferrel, from Horizons Regional Council, said water contamination would have been much worse if the truck and trailer had plunged down the bank into the stream.
"Most of the milk seeped into the ground so we were very lucky there was no serious contamination."
