Millions of pounds must be spent upgrading Breckland's waste water treatment works before large-scale house-building can begin to meet town expansion targets.

That is one conclusion of a detailed Water Cycle Study which will be presented to the district's develop-ment control committee on Monday.

The report assesses water supply, treatment and sewerage infrastruct-ure and looks at what improvements will be required to meet the needs of thousands of planned new housing estates.

Attleborough and Dereham are respectively targeted to provide 4,000 and 2,000 new homes between now and 2026. The study says both towns can cope with extra demands for clean water, but their waste water treatment works are already at full capacity and 'require immediate upgrades to accommodate additional homes and jobs'.

The costs, estimated at �7.5m in Attleborough and �1m in Dereham, will be met by Anglian Water, which was one of the organisations involved in the creation of the report.

David Spencer, Breckland Council's senior planning policy officer, said although there could be enough flexibility in the system to cope with small housing schemes, major building projects would have to wait until the capacity was improved.

'The purpose of this report is to understand the impacts of developments over the next 15-20 years in terms of the resources which are going to support those developments,' he said.

'The key messages are that there will be sufficient water available to meet future growth. But in a number of towns there is insufficient capacity at waste water treatment works to cope with the additional development, so they will need to be upgraded.

'Anglian Water has been part of the study. They are aware of what is going to be required and what they will need to fund in terms of those improvements.'

Mr Spencer said the exact details of the funding would not be decided until after Anglian Water's next asset management plan is published in 2015.

The report suggests an interim solution to the lack of capacity in Dereham could be achieved by phasing building projects of 50-80 homes per year, built to the highest water efficiency standards. In Attleborough, the solution requires a new pipeline from the treatment works to a new discharge point downstream on the River Thet.

Waste water treatment plants in Thetford and Swaffham will also need to be upgraded later during the plan period.

The report says that Watton and Swaffham are the only Breckland towns with sufficient fresh water supplies until 2026. Thetford, Attleborough and Dereham will require new ground water resources which could come from increased abstraction licences from existing boreholes and implementation of a new borehole near Carbrooke.

The study will help policy-makers finalise the district's Local Develop-ment Framework (LDF), a planning blueprint which will assist planners, landowners and councillors in the preparation and determination of future applications.