The EPA has received nearly 550 complaints from the Brimbank and Melton communities about odours coming from the Ravenhall tip in the past two months.
An EPA spokesperson told The Weekly it had received 86 in February and 460 in March.
Boral could receive fines if odours persist.
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“Odour investigations are complex and detailed, both because of the transient nature of odour, and the need to have an authorised officer confirm its presence in the field with the reporting witness present,” the spokesperson said.
“Despite numerous checks at various points within the community, we have not confirmed odours with residents. We have detected occasional odours near residential areas.
“Out of 175 individual odour checks we have detected no odour 144 times, weak odour 16 times and strong odour 15 times.”
She said odours were usually 70 per cent caused by composting and 30 per cent from landfilling.