Two tyre-burning kilns at its plant in Westbury were found to have exceeded permitted emission levels of hydrogen chloride and oxides of nitrogen. The agency said it was now satisfied corrective measures were being taken.
The company burns waste tyres for fuel, but stricter emission limits came into force last December. New abatement equipment and improved process controls are being introduced over the next few months to an agreed timetable.
Jim Flory, from the Environment Agency, said: "We will continue to closely monitor the improvement work and the emissions from the site.
"The emissions are set well below environmental thresholds and safety limits, so they will not affect the environment or the health of the public."
