Globs of fat spilled on to the road, into drains and the Ahuriri Estuary in Hawke's Bay on Monday afternoon after a truck carrying a tankful of fat ruptured a valve, leaking 6000kg to 8000kg of fat.
Hawke's Bay Regional Council spokesman Ian Lilburn said most of it was contained although a small amount reached the estuary due to troubles with a water gate.
Witness Glenn Allan helped break the locked water gate with a sledgehammer.
The regional council, Napier City and Hawke's Bay District Health Board quickly came together to clean up the spill and minimise environmental impact.
District Health Board Medical Officer Lester Calder said the fat had been heat treated so posed no risk to the public.
