Investigations by Wicklow County Council will resume this morning into a potentially huge illegal dump on lands owned by Roadstone Dublin near Blessington.
Roadstone said last month that household and commercial waste had been placed on the site without the company's knowledge or approval.
The council said an examination of the Roadstone site was now under way to assess the extent of the dumping. It said the investigation would include an assessment of potential environmental risks involved.
However, although it has a 500-acre holding in the area, Roadstone is not the only owner of land at Dillonsdown. The council thinks an investigation of sites at Dillonsdown is likely to take some time.
It is believed that the waste on Roadstone land may have been dumped at night by unscrupulous hauliers.