'Immense' illegal waste dump found outside Londonderry
The Environment Minister Alex Attwood has closed down a waste plant in Londonderry as part of an investigation into allegations of waste crime.
The investigation also uncovered a large amount of illegal waste found buried under soil and clay in land around the Mobouy area.
There is no suggestion the two are linked.
A statement from the DoE described the investigation as "unprecedented".
It claimed tens of thousands of tons of waste have been illegally deposited in a number of areas of land in the Mobouy area, just outside Derry.
Environment Minister Alex Attwood said, following intelligence received in 2012, he instructed the environmental crime unit to undertake a full-scale investigation.
Two people have previously been arrested and Mr Attwood said further arrests are expected as the operation continues.
"This has been painstaking work with the aim of maximising the chances of dealing a big blow to serious criminality and a big blow to environmental vandalism," he said.
"The scale of the unlawful waste activity is immense and appalling and dates back at least until 2009.
"It is sophisticated in its deception. Material was mangled and shredded to hide its original sourcing, with illegal landfills being top-filled with soil and clay to deceive and hide illegal waste."
The owners of the land used for the disposal have received legal notices requiring them to take action to prevent environmental damage by removing polluting liquid for disposal elsewhere.
The waste management facility that has had its licence revoked will cease to operate from close of operations on Wednesday evening.
The operators will then have two months to deliver all the remaining waste to a landfill site for disposal.