The water from our taps is not pure. Water is a good solvent and picks up impurities easily. Water described as "hard" is high in dissolved minerals, specifically calcium and magnesium. Hard water is not a health risk, but can be a nuisance because of mineral build-up on heating elements of household products - thereby affecting their performance and service life. Hard water can also affect detergent performance. A simple way to see if you live in a hard water area is to look in your kettle and see if there are deposits on the heating element.

The following map indicates regions of the UK and the hardness of water supplies.

For further information on hard water in the UK, visit www.dwi.gov.uk/pubs/hardness