Power plant boiler used without air filters

A boiler at the Marsa power station was pumping unfiltered emissions into the sky for seven months after its filtering system was switched off, The Times has learnt.

The air filters, called electrostatic precipitators, at the ageing power plant were turned off on one of the boilers for "operational reasons" between March and October, a spokesman for the Malta Environment and Planning Authority (Mepa) confirmed.

Now, the precipitators have been switched back on. However, when they are off, emissions are discharged without being filtered.

The March to October period coincides with a rise in complaints from residents in the Fgura area over black dust deposited on rooftops, balconies and cars.

However, while not specifying what the "operational reasons" were, a Mepa spokesman said the dust emissions from the boiler's activity were still "well within" its stipulated limits.

Fgura mayor Darren Marmara said the council saw an increase in complaints around June and these continued until October.

Last July, Tarxien mayor Pawlu Farrugia had publicly called for action to be taken after the mysterious black dust reappeared in his village. Although a report drawn up by British experts nine years ago had indicated the Marsa power station as a likely source of the black dust that intermittently plagues the southern harbour area, a Mepa report last year was inconclusive.

The authority is still studying the matter and fresh samples are being collected for deeper analysis.

Enemalta, which operates the island's only two power stations, is obliged by law to inform Mepa whenever it switches off the electrostatic precipitators. The corporation twice this year switched off the precipitators on another two boilers: on January 1 and 9.

The Marsa plant has equipment which continuously monitors emissions. Emissions from all plants in service at Marsa, the Mepa spokesman said, were "typically half the level permitted".

The precipitators are part of a number of measures designed to ensure dust emissions from the plant do not exceed the limit values, he added. Other measures include the use of low-sulphur fuel and "operational conditions".