Some 100 metres underground, a network of man-made tunnels is filled with cool ground water – the crystal clear remnants of rain that fell on the island around 50 years ago.

The Water Services Corporation on Friday gave reporters a tour of the subterranean tunnels at the Kandja Pumping Station, along with an update on the €130 million water network investment project.

The project seeks to ensure uniform quality drinkable water in the taps of every home in Malta.

WSC chief executive Richard Bilocca said the corporation was well on schedule to complete the project which will increase the corporation’s ability to “blend” water produced at reverse osmosis plants with that extracted from the ground water table.

Some 158 tenders have been issued for the projects and some €37 million in EU funds have been released, Mr Bilocca told the Times of Malta.

He said the project would revolutionise the way water was produced and distributed on the island. Seawater desalination plants will be upgraded both in terms of efficiency and output, producing much more water with less energy.

Reverse osmosis energy requirements, he said, would be cut by around eight per cent.

The corporation is expecting to cut its ground water extraction by some 4billion litres every year, thanks to the project.

Meanwhile, deep underground a WSC engineer explains how the station was the last groundwater abstraction site to be constructed by the British.

The digging of the galleries and station shafts started in the early 1950s and the plant itself was operational by the mid-1960s.

How does the whole system work? Huge submersible pumps send the clear groundwater to distribution reservoirs with the Ta' Kandja pumping station pumping to Qrendi reservoir and then on to the Ta’ Qali reservoirs where it is blended with desalinated water from the reverse osmosis plants.

The corporation will now be boring a 9.5km underground tunnel to convey water from the Pembroke osmosis plant to the Ta Qali reservoirs, Mr Bilocca said.

The corporation will also be extending the sewer network to remote areas currently not connected to the grid. Parts of the sewage network that desperately needed upgrading to keep up with increased flow would also be seen to.

The corporation is also working to ensure that the sister isle will no longer be reliant on the mainland for its water supply as the WSC plans to develop a new reverse osmosis plant in Ħondoq.

The plant will produce up to 9,000 cubic metres of water every day and ensure self-sufficiency on Gozo.