We invested more than £45 million to upgrade processes at our water treatment works during 2010-11.

We upgraded the disinfection processes at 35 of our works as part of a long-term investment programme to continue to meet strict drinking water standards.

The work included enlarging tanks and water mains where chlorine is added and either replacing or installing new ultra violet equipment. Both processes help to disinfect drinking water before it is pumped to customers’ taps.

Monitoring equipment was also upgraded at all of our water treatment works, using the latest technology. The new triple validation system monitors water quality before water enters the works and after it leaves. This ensures accurate and reliable readings and prompts a works to shut down if a problem ever occurs.

If the monitors detect water that is not of the highest standard, the works will automatically shut down to stop it going into supply.