Investigations are underway into illegal tyre dumping in the Muff area.
Two incidents have been reported this week, but the issue has been ongoing for some time.
County Councillor Terry Crossan has called on the public to report any sightings of those responsible.
He said: “This is becoming all too frequent.”
A large number of tyres were reported on the Alder road on Thursday and more than 40 tyres were dumped at the side of the road in the middle of the Lis na Grá woods earlier this week.
Cllr Crossan said that gardaí are examining CCTV footage in relation to the Lis na Grá incident.
He added: “Removal and disposal of these tyres incurs a cost that ultimately falls to the taxpayers. I would encourage anyone who witnesses this illegal dumping to report it immediately to either Gardaí, Donegal County Council or to myself giving as much information as possible.
“This needs to be stamped out!”