Fluoridation

Fluoride occurs naturally in most water supplies, though the actual amount present varies depending on the source. Some water supplies can contain fluoride if they originate from sources underground where there are rocks that contain fluoride-rich minerals.

Water supplies in the North West are naturally low in fluoride - and normally contain less than 0.2mg fluoride per litre.

Some water supplies have fluoride added to raise the concentration to 1.0mg per litre. This figure includes the fluoride that was already there naturally.

Why is fluoride added to water?

Fluoride is added to the water supply at the request of a health authority because a small amount of fluoride in the diet strengthens the enamel on teeth, especially in children.

Who decides where fluoridation takes place?

A health authority can direct a water company to fluoridate the water supply in an area if it is technically possible, but they must consult the public first before introducing any new schemes. The water company acts as a contractor and cannot refuse to fluoridate the supply if directed to do so.

On April 1 2013, the Secretary of State for Health became responsible for existing fluoridation schemes via Public Health England, and local authorities became responsible for proposing and carrying out consultation on new schemes and extensions to existing schemes.

Questions about existing fluoridation schemes can be addressed via the Public Health England area on the GOV.UK website. Any questions on possible future fluoridation schemes in your area should be addressed to your local authority.

Where does it happen now?

Agreements are in place between Public Health England and United Utilities which require artificial fluoridation at three of our water treatment works. Two of these works are in West Cumbria, at Cornhow and Ennerdale. The third is at Hurleston, in Cheshire. The agreements for fluoridating these supplies date back to the early 1970s.

Cornhow's works supplies water to Workington, Seaton, High Harrington, Great Clifton, Silloth, Maryport, Flimby and Cockermouth. Ennerdale's works supplies water to Whitehaven, Arlecdon, St Bees, Frizington, Salterbeck, Egremont, Cleator Moor, Beckermet, Ravenglass and Bootle in West Cumbria. Hurleston Water Treatment Works supplies water to Crewe, Alsager and Nantwich.

The population served from these water treatment works is a very small fraction of the total population supplied by United Utilities.

What is the process for introducing new fluoridation schemes?

The Water Act 2003 was given Royal Assent in November 2003. This legislation states that a health authority can direct a water company to fluoridate the water supply in an area, if it is technically possible. The authority must consult with the local community and businesses in the affected area. The water company will act as a contractor in any new schemes and cannot refuse to fluoridate the supply.

On April 1 2013, the Secretary of State for Health became responsible for existing fluoridation schemes and local authorities became responsible for proposing and carrying out consultation on new schemes or extensions to existing schemes. Any questions on possible future fluoridation schemes in your area should be addressed to the local authority where you live.

Who pays for fluoridation?

The health authority meets all costs associated with fluoridation of the water supply. This includes the cost of the chemical, maintenance of the equipment, monitoring and any additional sundry costs. The fluoridation of water does not have any impact on customers' bills in the region.

For more information, please contact us on us on 0345 672 3723. Dial 18001 first if you have hearing or speech problems.

How is fluoridation carried out?

There are currently two chemicals approved for the artificial fluoridation of water: these are disodium hexafluorosilicate (Na2SiF6) and hexafluorosilicic acid (H2SiF6). United Utilities uses hexafluorosilicic acid for its existing schemes. All products and processes that come into contact with drinking water must be approved. A list of all approved products and processes can be found on the Drinking Water Inspectorate (DWI) website (PDF 483 KB opens in a new window). The chemicals are generally added at the water treatment works. We must follow strict guidelines laid down by the Government detailing how water should be fluoridated artificially.

The fluoride concentration is continuously monitored as the water leaves the water treatment works. The maximum permitted concentration of fluoride in drinking water is 1.5mg per litre (1.5 parts per million).