The Center for Coalfield Justice said the Emerald mine near the town of Waynesburg had been illegally discharging pollutants, including “high levels of heavy metals”, into rivers for the past five years.

Coalfield Justice executive director Patrick Grenter said the group filed the suit with a federal court in Pittsburgh with a 60-day notice period for amicable resolution, but that Emerald decided not to respond.

“We cannot sit idly by while our rivers are continuously polluted,” he said.

“We have waited long enough for Emerald to stop illegally polluting our rivers and streams and now these ongoing violations must come to a stop.”

The lawsuit said the miner could be penalized up to $37,000 per day for the alleged environmental damages, civil penalties and costs of the legal action.