The dairy giant was granted resource consent in 2006 to discharge treated water to the river, but needs to reapply to continue the activity.

The river is known to be heavily polluted due to a combination of farm run-off and wastewater discharges from towns and cities.

It was infamously found in 2009 to be more polluted than 300 rivers and streams across North America, Europe, Australia and New Zealand when Cawthorn Institute published results of testing at one site on the river.

That led to the Manawatū River Leaders’ Accord – a pledge to clean up the river – which Fonterra signed.

Fonterra water and environment sustainability and resources general manager Ian Goldschmidt​ said the company planned to discharge less water from Longburn to the river if granted a new consent.

The company was investing almost $500 million during the next eight years to improve water quality at multiple sites, including initiatives to reduce water use, he said.

“Water is essential for manufacturing at our sites as we use it to maintain world-class food safety and quality standards, and for cooling our products.”

According to a Horizons Regional Council agenda, Fonterra has requested the consent be publicly notified, giving people the chance to make submissions.

A hearing date for the consent application is yet to be set.