The charts overleaf show the percentages of tests which passed the standards and also the figures for tests which failed to meet the standards. Other failures will be put right by improvements already being carried out by water companies - these involve treatment works and distribution systems and altogether cost many hundreds of millions of pounds. Any remaining failures will be addressed by us requiring water companies to carry out further improvements quickly. The Inspectorate has a duty to require water companies to take any necessary action. We check that improvements are being completed on time.
Disinfection kills bacteria in water.
Chlorine has been used to disinfect drinking water for more than a hundred years. Not all bacteria are harmful - some are easily detected. Whenever it is suspected that bacteria may have got into drinking water supplies the water company investigates immediately. Consumers may be advised to boil water to be on the safe side. If the sample was taken from a consumer's tap, and many are, then the problem may be no more than dirt on the tap.