An underused and vast reserve of water under the ground could help boost business expansion in Belfast, a study showed.
The Sherwood Sandstone Aquifer (SST) contains 20 times more water than Silent Valley which captures run-off from the Mourne Mountains in Co Down. Some of it could be thousands of years old and natural processes remove harmful chemicals and bacteria, Stormont's Economy Department said.
The natural resource below the Lagan Valley made Belfast the largest exporter of carbonated water in the world before the First World War and experts believe its enduring potential could be harnessed to attract new industry.
The Economy Department report said: "The Sherwood Sandstone Aquifer, has historically provided reliable water supplies for over a hundred years and the volumes currently being extracted are much less than those in the past when it was used extensively in the brewing, textiles and other industries.
"Current groundwater level monitoring suggests that the aquifer is capable of sustaining the current demand and is likely to be capable of sustaining significantly more sustainable abstraction.
"The coincidence of land zoned for business and industrial use above the SST aquifer would present an attractive prospect to businesses either seeking to expand, locate or relocate.
"Ensuring that such land remains available for groundwater abstraction is important to ensure the valuable groundwater resource is accessible."
The underground aquifer is formed from water seeping down through the rocks from the surface.
It stretches from Moira to Belfast and Newtownards and is located in a substrate below ground where temperatures remain well above freezing year-round.
The Economy Department report said it was the most regionally important aquifer in Northern Ireland.
Queen's University, Belfast's hospitals and the Coca Cola bottling plant near Lisburn are heavy consumers of ground water.
The Department said: "The prospects for a reliable and significant water supply from this aquifer are high such that it has been used extensively for water supply for the last hundred years."
It was also used to drive steam engines to power heavy industry but abstraction declined with the introduction of mains electricity.
In the 1970s the Lagan Valley Aquifer project saw an array of boreholes across the aquifer supplying mains water, with little or no treatment requirements.
Northern Ireland Water centralised production of water to Lough Neagh and stopped abstracting from the SST aquifer in 2008.
