Cross-Border fuel smugglers caused further pollution in Co Monaghan over the weekend in the Croghan area of Annyalla.
They dumped five plastic containers with almost 5,000 litres of diesel sludge – the substance “laundered” from coloured tax-rebated diesel when the dye is removed.
Removing the dye enables those processing the diesel to get a higher price for commercial fuel used by motor vehicles.
It was the third illicit dumping of sludge on the southern side of the Monaghan/Armagh Border within the week.
Monaghan County Council environment crews and the fire service were called in to clean up the area and prevent seepage into nearby farmland or streams.
Gardaí and farming organisations renewed an appeal yesterday for information that will help them to target the illegal dumpers.
The dumpers have cost Monaghan and Louth county councils more than €3.5 million in road-clearance operations during the past year.