Fonterra plans to change the way it gets rid of buttermilk after it was slapped with a formal warning by the Waikato Regional Council.
The company breached the Resource Management Act by dumping five million litres of the waste at Atiamuri last October - an action the council initially regarded as a "relatively serious environmental incident".
It eventually decided the discharge was not a hazard and Fonterra, the land owner and the person managing it received formal warnings.
The company said it would now require a land owner or manager to prove they had received council approval and consent to accept the waste, and both parties would agree on ongoing environmental monitoring.
Fonterra said it would cart milk to the company's various sites to use up their spare capacity during the peak of the season in spring.
It was also upgrading three plants so they could process dairy products which generated fewer by-products.
Fonterra said it would make more land available for irrigation with by-products such as buttermilk.