Facts about your Thames Water supply

The quality of drinking water supplied to our customers is of paramount importance to us:

• We supply around 2,600 million litres of water every day to 8.7 million customers, treated at our 103 water treatment works, and piped through a network of 31,000km of water mains stretching from the Cotswolds to South East London.
• Nearly three quarters of our water supplies are from rivers, with the rest from underground sources (aquifers).
• Over 400,000 laboratory tests are performed annually to check the quality of our drinking water.
• In 2009 over 99.98 per cent of these tests, as measured at consumers' taps, met stringent water quality standards.
• Water in our area is rated as hard, ranging from moderately hard to very hard. The exception is a small area south of Guildford where slightly softer water is abstracted.
• We do not fluoridate any of our water supplies, and any decision to do so would be taken by your local strategic health authority, following public consultation.
• Our drinking water contains low levels of chlorine which ensures the water is safe to drink, and serves to protect public health.