Reports on social media alerted authorities to a Pandora industrial area spill in which thousands of litres of tallow and water flowed into Napier's Ahuriri Estuary.
Hawke's Bay Regional Council resource use manager Wayne Wright said it was the posting of images and comments on social media that alerted the staff about 1.30pm on Monday, not any calls to the council or pollution hotline 0800 108838.
"The discharge had been noticed several hours earlier by members of the public with photographs and comments posted on social media, however the regional council was not contacted directly," Mr Wright said yesterday.
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He said staff would attend immediately when incidents were reported, and added: "It is better to be safe than sorry and there's no such thing as a bad call.