Gardai in Co Monaghan are appealing for information after three liquid cubes containing diesel sludge were dumped in Carrickmacross.
The containers are believed to have been left in the Mullanavannog area of Donaghmoyne between Tuesday the 17th of January and Wednesday the 18th of January last.
Monaghan County Council is currently working to limit the environmental impact.
Meanwhile, Gardai want to speak to anyone who noticed anything suspicious in the area at the time of the incident.
Anyone with information or who may have observed a vehicle carrying the cubes is asked to contact Carrickmacross Garda Station on 042 9690190.