Making it safe to drink

We work 24 hours a day, 365 days a year, to ensure the water we supply to our customers is healthy and safe.

The majority of water we supply is pumped from underground aquifers and this water is relatively easy to treat.

It has already been naturally filtered through chalk or sandstone, and  only needs to be disinfected with chlorine to make it safe to drink.

Water taken from rivers and surface reservoirs – requires more treatment stages to ensure the water is of the highest quality:

  • Storage

As water is stored in reservoirs, debris and solids settle to the bottom and sunlight breaks down organic material.

  • Screening

Water passes through fine screens, removing larger material such as sticks and weeds.

  • Primary Treatment

Ozone gas is bubbled through the water and a form of iron is added. This process forms small particles, called ‘floc’, which attract impurities.

  • Clarification

The floc is stirred to increase the size of the particles, which sink to the bottom and are removed.

  • Filtration

Filtration sieves the water, and using slow sand filters also encourages bacteria to grow, breaking down organic compounds in the water.

  • Aeration

This process removes compounds such as hydrogen sulphide and carbon dioxide, and oxidises dissolved metals.

  • Advanced Treatment

Water is treated with granular activated carbon (GAC), while ozone gas is bubbled through it. This disinfects the water, and removes pesticides.

  • Disinfection

Chlorine disinfects all water supplies, to eliminate potentially harmful micro-organisms such as bacteria.

  • Sludge Treatment

Finally, waste products produced during the treatment processes are themselves treated, with clean water returned to the environment and solid matter recycled into fertiliser.