Every day Southern Water supplies nearly 600 million litres of water to almost one million homes, as well as industry and businesses in our supply area.

We collect water from natural underground sources, which account for two thirds of our supplies. as well as rivers and our five surface reservoirs.

The water is treated at more than 100 water works across the South East before it is pumped to huge underground storage tanks ready for pumping along the mains to customers' taps.

The level of treatment the water requires depends on where it comes from but can include several stages of filtration and disinfection with chlorine.

The water supply from your tap undergoes far more stringent tests than bottled water.

Water is continuously tested before it is put into supply and each year we carry out more than 600,000 tests, checking for more than 100 different substances.

An independent laboratory analyses the samples and the Government's Drinking Water Inspectorate monitors the results.