A one-man crusade to get to the bottom of a sewage flooding issue in Dereham has forced an admission by a water company that it gave the wrong advice to a housing developer over capacity in Dereham's drains.

Neil Starling, who has spent weeks trying to get to the root of why raw sewage is bubbling up from manhole covers in Norwich Road, has been told by Anglian Water that its advice had 'caused confusion and been open to misinterpretation' after it told Taylor Wimpey there was sufficient capacity in the drains in Dereham to connect a new development of 226 homes to the main sewage network.

The developer was given planning permission for the homes by Breckland Council with a condition that it removed the sewage from underground storage tanks by tankers until the sewerage network could be upgraded and foul water taken to a new improved waste treatment plant at Mattishall.

But in June Anglian Water told Taylor Wimpey that it had carried out work to enable to the homes to be connected to the main drains, at a build rate of 50 properties per year.

The developer connected to the drains in Norwich Road and has applied for the condition to be removed.

But, under increasing pressure and investigation work from Mr Starling which revealed the waste was heading to the already at capacity Dereham treatment works, Anglian Water's growth and planning manager Kathryn Taylor admitted the company 'cannot maintain the position stated in this letter'.

She added: 'The letter refers to improvement/mitigating works making capacity available. These mitigating works have not taken place. Whilst this was not known at the time the letter was written they were fully expected to occur. Greater diligence within the team would have resulted in the statement not being made until the works had indeed taken place or the statement would have been contingent on these works taking place.'

She said the water company had recommended that Breckland Council enforce the condition requiring sewage to be removed by tanker.

A spokesman for Taylor Wimpey said they had proceeded with the connection works 'in good faith' and had not been notified that upgrade works had not been completed by Anglian Water, only finding out through a local resident.

'Naturally we were extremely concerned,' she said. 'We have raised this issue with Anglian Water as a matter of urgency and will be working with them to resolve the problem as quickly as possible.'

Breckland is set to discuss the removal of the condition in the next few weeks and also a planning application for a further 62 homes on land west of Etling View.

Mr Starling, who lives in nearby Windmill Avenue, said he felt the sensible outcome was that the developer would have to disconnect from the main drain and renew its daily tanker visits to the site to empty the tanks.

'What upset me most is when there is sewage flood water on the pavement outside the schools and kids are walking through it with no idea what it is,' he said. 'That is what spurred me on and I feel it has been time well spent if anything comes of it. I don't lay all the blame at Taylor Wimpey's door but clearly the more houses are built the worse it will get.

'I have tried to do the right thing and bring it to the attention of the people who make a difference.'

•Do you have a problem with sewage flooding? Email kathryn.cross@archant.co.uk.