Fumes have escaped from the new Delimara power station’s fuel tanks but Enemalta insists they did not cause the foul smells reported by Marsaxlokk residents.

These are massive tanks and the heating system cannot be switched off

In the latest problem to beset Malta’s power stations, Enemalta confirmed the fumes leaked out an air vent because of “a missing pressure valve”.

“This has been ordered and is expected to be delivered soon, after which it will be installed on the tanks,” a company spokesman said.

Planning authority inspectors had recorded the smell in the vicinity of the tanks that store heavy fuel oil used in the new plant.

“It was barely noticeable in other areas of the station and so it would be unlikely for the smells to reach Marsaxlokk,” she said. The company installed temporary water seals on the tank vents “to minimise any emissions”, she added.

“The water seals are working well and there are hardly any noticeable smells in the vicinity of the tanks.”

The tanks are equipped with charcoal filters that absorb oil vapours and release clean, odourless air. But the unfiltered air escaped from the second air vent that equalises pressure inside.

However, sources who spoke to The Sunday Times have insisted the foul smells in Marsaxlokk are likely to have been caused by the fumes.

Although heavy fuel oil has been used in Delimara since 1992, the temperature of the oil in two large tanks supplying the old plant is maintained at a relatively low40 degrees Celsius. However, the new plant’s more efficient engines have to be supplied by fuel oil heated in excess of 90 degrees Celsius, which produces “substantial amounts of fumes and vapours”, the sources said.

“Unless the filtering system is replaced with a more effective system, the problems will persist,” the sources said.

When Enemalta was asked whether it will replace the filtering system with something more effective, the spokesman said the plant was still being tested.

“It is expected there will be faults that the contractor will need to resolve prior to the plant being accepted by Enemalta.”

She said after the missing valve was installed and other minor modifications made, the tank filtering system was expected to be“fully effective”.

If the filtering system failed to perform it would have to be modified or replaced. “This does not appear to be necessary in this case.”

Enemalta said complaints generally referred to the “smell of burning tar and burning plastic” and were usually reported at night.

“The fact that in the testing period the extension isn’t used at night means there are no changes to the fuel tanks and there are no emissions from them,” the spokesman said.

But sources indicated the fuel storage tanks would still let off fumes at night because the oil requires heating.

“These are massive tanks and the heating system cannot be switched off, especially if the oil has to be in the right condition for use in the morning.”

The new plant is currently undergoing test runs. Last week The Times reported that some exhaust filter bags which were supposed to last two years were damaged after a few months.

Enemalta said it was investigating the cause and insisted the damage was minimal and did not affect chimney emission levels.

ksansone@timesofmalta.com