ONE of the companies behind Dublin's Poolbeg incinerator project, Covanta Energy, has been fined by the US government for numerous breaches of fire-safety rules at its American operations.

The Sunday Tribune has learned that US safety officials found explosive gases being stored in dangerous conditions, broken equipment repaired with cardboard and duct tape and improper electrical wiring during a series of inspections at its massive SEMASS plant, which is close to Boston.

Officials have been closely monitoring the plant's activities since an explosion in 2007 triggered a fire which burned for two days and caus­ed €12.8m worth of damage.

A subsequent investigation into the SEMASS fire criticised the company for failing to make employees fighting the fire wear suitable protective clothing. It also found the facility's use of fibreglass ducting had helped the fire to spread.

Due to the weak nature of US employment law, it was fined less than €15,000 despite 10 serious breaches of safety rules being identified during the inspections.

Covanta is the main shareholder in the Poolbeg project with a minority stake held by its Danish partner Dong ­Energy.

The Sunday Tribune has also learned the company is currently being sued by the US National Labour Relations Board for withholding bonuses and pay increases from employees who have joined a union.

The union involved, the Utility Workers Union of America (UWUA), has also claimed that Covanta im­posed a secrecy clause on its employees, preventing them from talking to safety officials and representatives of external agencies.

The clause stated that when dealing with such individuals, "the employee must immediately notify the employee's supervisor, manager or department head and must not provide any information… unless specifically authorised to do so".

According to union official Mark Brooks, the UWUA remains concerned about safety at the SEMASS plant and Covanta's treatment of its employees. "[The breaches] were corrected after the inspection, of course, but in our view it is completely unacceptable for a company operating an inherently hazardous facility such as a waste incinerator to permit potential fire hazards," he said.

But Covanta's European president, Scott Whitney, insisted the company was a responsible organisation and that the same issues wouldn't arise at the €350m Poolbeg facility. "Less than superior safety conditions and perform­ance are unacceptable and represent a significant departure from normal operations," he said.

A Dublin City Council spokeswoman said that it was satisfied that "Covanta has the capabilities to operate the plant to the highest health and safety standards and will prioritise the protection of staff and the wider public in accordance with the relevant standards".