Approximately 2,000l of milk overflowed from a milk silo at Aurivo's processing plant in Ballaghaderreen, Co Roscommon, on Saturday 30 April.
Aurivo said in a statement that the "technical issue" on Saturday night was due to an upper limit probe system failure, which caused an overflow of around 2,000l of milk from onsite tanks.
"The issue was promptly resolved – within minutes. The spillage in question was contained in a retention tank and subsequently removed for treatment," a spokesperson said.
The Ballaghaderreen facility mainly manufactures milk powder products and nutritional ingredients.
Just last year, Aurivo installed a new dryer in Ballaghaderreen which produces various grades of enriched milk powder.
This allows Aurivo to process 35% extra milk per week.