A Ballyhaunis company is among five sites listed by the Environmental Protection Agency as National Priority Sites for Enforcement.
Five sites have been included on the latest list for failing to meet the necessary environmental standards - including the Western Brand Group in Ballyhaunis.
The EPA says these companies face further enforcement action.
Meanwhile, Aurivo Dairy Ingredients Ltd in Co Roscommon has been removed from the National Priority Site List, following improvements in compliance and reduced risk.
The EPA has also published its Industrial & Waste Licence Enforcement Report for 2017, which gives details of compliance levels and enforcement activities across 800 licensed facilities.
22 prosecutions were taken last year, with 16 convictions, and fines worth over 374-thousand euro were issued for failings in industrial waste management.
The report shows that over 1,000 complaints were received in 2017 about licensed facilities, with 73% of complaints relating to noise and odour.
Among the top ten most complained-about facilities were the East Galway Residual Landfill site which accounted for 57 complaints, while there were 23 complaints about Shell E&P Ireland Ltd.