Marsa power station does not have filters on its chimneys to collect soot but uses electrostatic precipitators installed on the main boilers to collect dust, Infrastructure Minister Austin Gatt said in Parliament.

He said that there was no legal requirement for Enemalta to install the filters, and it had no plans to do so.

The level of emissions is kept low and within permissible levels primarily through the use of oil with low sulphur content.

The precipitators were installed when the power station was coal firing and they were converted to oil-firing operations in 2000.

The minister also explained that last year Enemalta installed instruments to monitor dust emissions. The results showed that the emissions were almost always constant and there was no significant variation during the time when black dust was reported over several localities.

Furthermore, Mepa tests on the dust found in the localities showed that it lacked the chemical composition which would have shown that it came from the power station.