Mechanical and electrical equipment is being installed at Severn Trent's sewage works in Alfreton.

There will also be facilities to remove phosphorous and ammonia from the water making it cleaner when it returns to the Alfreton brook.

The project, part of a wider �140m, programme, is due to be completed by the end of the year.

Jonathan Bailey, Severn Trent Water's director of customer relations, said: "Whilst prices have risen to fund this investment programme the average household bill in the Midlands will still be among the best value in the country.

"Above all, the prices we charge need to ensure we can continue to invest in our water pipes, sewers, and water and sewage treatment works so our customers will see the benefit."