Talleys-owned Open Country Cheese's has been accused of running its Waharoa plant in Waikato without appropriate trained staff leading to serious environmental damage.
Thirty six workers have been locked out of the factory after walking off the job on Wednesday night over a pay and contracts dispute.
OCC has brought
in outsiders to keep production going.
James Ritchie, national secretary of the Dairy Workers Union, said today untrained staff were now operating the plant.
"Environmental management is a critical part of any dairy operation but OCC wants to drive production at any cost," he said.
"Today the environmental ponds overflowed with deactivated sludge and poured into the river.
"The sludge tanks need to be managed by trained staff and is a critical part of the manufacturing process.
"Normally the sludge is collected by trucks and spread on farms, but we found out this morning that it had been poured directly into the Waitoa river."
Mr Ritchie said Environment Waikato had been notified of the damage.
The company was not available for comment this morning.
- NZPA
