A project which will lead to minimally-treated sewage being pumped out to sea off the north Suffolk coast will not cause a reduction in bathing quality, it was claimed last night.

A project which will lead to minimally-treated sewage being pumped out to sea off the north Suffolk coast will not cause a reduction in bathing quality, it was claimed last night.

Anglian Water (AW) has announced a major £1½m maintenance and upgrade programme at its Lowestoft Waste Water Treatment Centre, resulting in sewage being less thoroughly treated for about six months.

A public consultation exercise is launched today and company bosses insist the work will be perfectly safe, although the Environment Agency still has to give the project the green light.

Last night, Waveney MP Bob Blizzard said he accepted the work needed to be done, but stressed he would be watching closely to ensure the project was finished on time.

The £70m centre was only opened in 2001 and is unlike most other sewage plants because it is fully enclosed to prevent smells blighting local residents' lives and also to make it less of an eyesore. However, its design means that corrosive gases have been harder to disperse and have caused a quicker deterioration of equipment than would be expected at more traditional plants.

AW has revealed the work will take place between this October and the following April to avoid the main tourist season and that it will bring back into use a pipe, known as the long sea outfall, which will pump the waste water further out to sea.

Sara Rowland, AW's media manager, said: “By choosing this time of year and by using the long sea outfall, we are satisfied there is going to be no environmental impact and nothing for people to worry about.

“We have got one of the best records for bathing water quality in the UK and the best in England. A lot of effort has gone into achieving that for the benefit of the local economy. We are keen not to compromise that and the work is not something that has been undertaken lightly. Every consideration has been given to how we can do this with the minimal environmental impact.”

The maintenance work will see parts of the plant shut down over the six-month project and lead to only primary, or minimal, treatment of waste water to filter out larger objects from the sewerage system.

This means that what is pumped out to sea will still be murky in appearance, but Miss Rowland insisted an independent assessment carried out by environmental experts on behalf of AW showed the procedure was safe.

She added that the longer waste pipe, which will take water out to sea at Ness Point in Lowestoft, has not been used since the opening of the new plant at Corton, but was still fully operational and extended out to about a mile off the coast.

As well as repairing damage to the concrete tanks at Corton, a new lining will be sprayed on to provide longer-term protection, while work will also be carried out to improve equipment that converts methane gas into energy to power the plant.

A spokesman for the Environment Agency said: “It's our responsibility to make sure it doesn't put water quality standards at significant risk and to ensure the sewage is treated properly.”

Mr Blizzard, who has been briefed by AW about the work, said: “The important thing is to keep to the time-scale and I will be watching them very closely to make sure it doesn't drag on and that sewage isn't pumped into the sea for longer than is necessary.”

Residents in the Corton area launched a high profile campaign against AW's plans to open the new plant, saying the company should consider alternative sites. However, relations have improved in recent years.

t Details of how to comment on AW's proposals are available in the public notice published on page 46 of today's EDP.