Power consumed to produce water has fallen by a third since 2004, thanks to measures to raise the energy efficiency of reverse osmosis (RO) plants. A decade ago the electricity used to produce water from RO plants, groundwater and the Sant’Antnin wastewater plant amounted to 4.8 per cent of total consumption on the island. This dropped to 3.2 per cent last year.

Data published yesterday by the National Statistics Office on the occasion of World Water Day showed RO plants remained the main source of water production.

Last year, they produced 16.8 million cubic metres while ground water extraction by the Water Services Corporation amounted to 13.8 million cubic metres.

While total water production in 2004 reached 32.7 million cubic metres, last year it was 30.6 million.

Between 2004 and last year, the average consumption to produce one cubic metre of water from RO plants was 4.6 kilowatt hours, almost six times that to extract groundwater (0.8 kilowatt hours).

The data indicated a significant drop in the volume of waste water treated at the Sant’Antnin plant in Marsascala. In 2004, it treated 2.6 million cubic metres, which fell to 1.9 million cubic metres last year.