MAINS water supplies in east Suffolk could be put under stress if permission is given to build a �6billion Sizewell C nuclear power station, according to critics.

MAINS water supplies in east Suffolk could be put under stress if permission is given to build a �6billion Sizewell C nuclear power station, according to critics.

Figures revealed to a local watchdog group show that the existing Sizewell B plant uses about 800 cubic metres of mains water a day - estimated to be about 7pc of the total demand in the local catchment area.

Critics say based on this figure a twin-reactor Sizewell C would demand a further 1,600 cubic metres a day - in one of the driest parts of the country and where householders and businesses have in the past few decades faced restrictions on use.

Figures for water consumption at the Sizewell nuclear site were disclosed at the quarterly meeting of the Sizewell Stakeholder Group - set up to improve liaison between the local community and the nuclear site and Government agencies - following a request from one of its members, Joan Girling.

The Sizewell site uses water supplied by the Essex and Suffolk Water Company, part of Northumbrian Water, in order to cool various parts of the plant, including the primary and secondary circuits of the reactor - the radioactive heart of the power station. For the latter use, it is treated to achieve a higher purity.

Figures for Sizewell A, which ceased commercial operation in December 2006 and is now being decommissioned, show that it currently uses 120 cubic metres a day.

Both the A and B stations also use large amounts of sea water - for cooling areas of the plant where use of mains water is unnecessary.

While in commercial operation, Sizewell A used up to 34 cubic metres of seawater per second compared with its current usage of 18 cubic metres per minute.

Sizewell B is permitted to use up to five million cubic metres of seawater per day and this is discharged back into the North Sea.

Ms Girling, a former county, district and Leiston town councillor, said the figures revealed the scale of mains water already used by the Sizewell site.

“The amount is almost unbelievable and I cannot see how the water company is going to avoid problems if Sizewell C is built,” she said.

Her partner, Mike Taylor, a former town councillor who has been investigating local water demand issues, said: “There is no doubt that water resources are going to be under increased stress in future years if Sizewell C goes ahead.”

He added: “Water resources will become more stressed in the future as some boreholes may be lost to sea level rise or erosion.

“Any future requirement for new nuclear build plus any future new housing in the area takes out any reserve in the system and implies that a desalinisation plant may be required.”

It is understood that EDF, which owns the Sizewell C site, will look to mains water rather than bankroll the huge investment needed to construct and operate a desalinisation plant.

John Devall, spokesman for Essex and Suffolk Water, said the company had recently carried out an assessment of the next 25 years and, even taking into account the demands of a Sizewell C, the conclusion was that water supply would be sustainable.

However, it would be necessary to sink a new borehole north of Lowestoft to boost supplies.

Mr Devall said the assessment had taken into account housing and population growth and the climate change scenario of drier summers and wetter winters.

The work had been scrutinised by both the Environment Department (Defra) and the Environment Agency.