THE largest and most technically advanced water filtration plant in the world has opened in Bushey.

The ultrafiltration membrane works, at the Three Valleys Water site in Clay Lane, is now treating drinking water for about 750,000 people in north west London, including Bushey, Radlett and parts of Watford.

The £10 million new plant, unveiled by TV scientist professor Heinz Wolff, is the first of a planned series in the area.

A spokesman for Three Valleys Water said the investment would not effect customer bills.

She said the charges were set by OFWAT, the water regulator. However, unlike other privatised utilities, such as telecommunications and gas, water companies can impose above inflation price rises.

The spokesman said she did not anticipate water shortages in the area this year and stressed the efficiency of the new plant.

They also said past problems with pipe leakages had been largely addressed.

The new filtration technique is more effective at removing impurities, including pesticides, than previous methods.

The Three Valleys spokesman stressed water cleaned in the old way was safe.

Ultrafiltration takes out particles 300 times smaller than a human hair and will make the water safer.