Natural Resources Wales (NRW) has shut a scrap yard to stop it polluting the local environment.
The regulator said the site, managed by Clwyd Breakers at Gardden industrial estate, Ruabon, was one of the worst in Wales.
Operators broke the terms of their permit despite repeated interventions by NRW officers and this has now been revoked.
End-of-life cars can no longer be stored or dismantled there, and the site has been cleared.
NRW officers found, among other faults, visible oil pollution on all parts of the site, incorrectly stored waste and a lack of any fire prevention plan.
Some oils and other polluting fluids were being washed into drains which eventually flow into rivers.
Senior environment officer Louise Peel said: “We’ve worked really hard with the company to get them to operate the site responsibly, but it became clear that they were making very little effort to do so.
“The good news is that the site has now been cleared and it no longer poses a threat.”
The NRW is investigating another suspected illegal waste site in the area and its potential links to the cleared site.