Castle Cement has been fined £250,000 for dust and noise nuisances at its factory in Flintshire, Wales, plus two fires which released potentially dangerous smoke.
The company, part of the Hanson / Heidelberg Cement Group, pleaded guilty at Mold Crown Court to four charges relating to incidents between August 2005 and May 2007.
Castle Cement, which was also ordered to pay more than £55,000 in costs, asked for a further offence, involving an escape of 250 tonnes of dust from a broken pipe in October last year, to be taken into consideration.
The offences occurred following the commission of the new £70m Kiln Four which replaced three earlier kilns in August 2005.
The court heard the company had been fined £99,000 in March 2006 for breaches involving the release of dioxins from the old kilns.
In mitigation, the company had co-operated throughout the investigation and had pleaded guilty at the earliest opportunity.
The judge said he was satisfied the company had invested £1.8m trying to improve procedures.
The Environment Agency Wales said the fine and total costs were “one of the highest ever awarded for an environmental offence in the UK”.