The Delimara power station extension would produce about a tonne of heavy fuel oil sludge per day, three environmental NGOs have warned, calling for the problem to be tackled immediately.
This sludge could not be disposed of with other hazardous waste because of its physical and chemical nature, the NGOs - Friends of the Earth, Flimkien għal Ambjent Aħjar and the Ramblers' Association - said.
The environment impact assessment, they said, suggested that the sludge should be burnt at the Marsa incinerator but the Malta Environment and Planning Authority had ruled out this option.
The public needed to be informed of the proposed solution so this did not become another "black dust issue".
"There must not be a repeat of the black dust charade, where Mepa, waking up from a four-year sleep to find Enemalta sending Marsa fly ash to an unlicensed quarry, summarily stopped the transfer.
"This meant that, as soon as the Marsa ash store was full, Enemalta switched off the Marsa precipitators, showering the surrounding areas with 200 tonnes of hazardous fly ash," the NGOs said. They called for the Delimara power station extension to work on diesel instead of heavy fuel oil, saying the nation deserved no less. The Finance Minister's assertion that the use of diesel would result in an immediate rise of 30 per cent in electricity bills was "completely wrong", they said.
"With Marsa (power station) switched off, the extension working flat out would provide less than half our needs. That means the average cost of a unit will go up by 15 per cent at most and not by 30 per cent."
The figure could probably be cut down further and would also be offset by lower pollution-related healthcare costs.
The organisations said that operating the power station on heavy fuel oil would generate about 30 tonnes of hazardous waste a day from the clean-up of its chimney gases and it was incorrect to claim this waste was merely an irritant, as the government had done.
The particulate matter from the power plant engines contained heavy metals like vanadium and nickel abundant in heavy fuel oil, in addition to the poly-aromatic hydrocarbons (PAH) carcinogens common in diesel engine exhaust.
This imposed strict conditions on the collection, storage and transportation of the waste. The intention to transport the waste by road to the Freeport would increase heavy traffic through Marsaxlokk and Birżebbuġa, and expose residents to toxic emissions from the heavy emission of particulates with PAH from the container truck exhaust, the NGOs argued.