How Good is the
Drinking Water?
2002

Drinking water quality

Our main task is to check that the water companies in England and Wales supply water that is safe to drink and meets the standards set in the Water Quality Regulations. Inspectors carry out technical audits of each water company. Inspections are in two parts.

1. The results of drinking water tests by the water companies are rigorously checked. 2. Each water company is visited and specific aspect of operating practice inspected. Water quality is assessed on the basis of information provided by the water companies. Millions of tests are made each year to see if water meets the standard set down in law. Tests are carried out at water treatment works, in the distribution systems and at consumers' taps in designated geographical areas called water supply zones. We check the test results and carry out inspections to ensure that the results are reliable and give a true picture of the quality of the water supplied. We also investigate consumers' complaints and incidents that affect or could affect drinking water quality. Investigations of incidents can lead to water companies being prosecuted. We publish a leaflet Problems with your drinking water, which describes consumer complaints, investigation of incidents and prosecutions. This is obtainable free of charge from us on request.

A typical inspection may include checks to ensure that:

If problems are identified, we take action to ensure that the water company concerned rectifies the situation.

What are the standards?

	The Government has set legal standards for drinking water in the Water Quality Regulations. Most of these standards come directly from a European law and are based on World Health Organisation guidelines. The UK has additional standards to safeguard the already high quality of water in England and Wales. The standards are strict and generally include wide safety margins. They cover:

A European Community Directive which came into force in 1998 contained new standards and some changes to existing standards. New regulations were made at the end of 2000 to implement this new Directive. The water companies were required to meet the new standards by the end of 2003. Improvements needed to meet these new standards have been identified by the DWI and action is being taken by the water companies.

How good is our drinking water?

Drinking water is of a very high quality. In 2002 the water companies in England and Wales carried out approximately 2.9 million tests on drinking water samples of which 99.87% passed. This is better than in 2001 and continues the trend of continuous year on year improvement. The charts below show the percentages of tests, which passed the standards and also the number of tests, which failed to meet the standards.

Figures for percentages of tests passing the standards

Figures for the number of tests failing to meet the standards

How are failures to meet standards dealt with?

Each failure is assessed. Some are not important in terms of health or unlikely to happen again, so no further action is needed. Some failures will be rectified by improvements already underway at treatment works and in the distribution systems operated by water companies. The DWI requires the water companies to deal with any remaining failures by committing to immediate improvements. As part of the inspection process, a check is made to ensure that all such improvement work is carried out in a timely and appropriate manner.

Micro-organism and small traces of chemicals substances may occasionally be present in water.

	Bacteria Untreated water may contain bacteria, although these are not necessarily harmful. Disinfection kills bacteria in water. Chlorine is used to disinfect drinking water and has been used successfully for almost one hundred years. Water companies monitor the effectiveness of disinfection continuously and test for bacteria. When there is a risk of contamination, for example, following a burst pipe consumers may be advised to boil water as a precaution while investigations are being carried out. In 2002, the standard for bacteria was met in 99.48% of water supply zones. This is similar to the result achieved in 2001.
	Cryptosporidium Cryptosporidium is a micro-organism found in man and animals in many parts of the world. It can cause a disease called cryptosporidiosis. Water can be a source of the organism as can food, milk, contact with animals, particularly lambs and calves, other infected persons and swimming pools.
The organism multiplies in the gut of infected people or animals forming tiny spores called oocysts, which are then excreted in faeces in very large numbers capable of transmitting the infection. Oocysts can survive for months in clean water or moist cool soil. In humans, cryptosporidiosis causes diarrhoea usually lasting about two weeks before full recovery from the illness. It is not very common, but in people with severely depressed immune systems, the disease becomes more serious. In such cases all water should be boiled before drinking, whether tap or bottled. Much has been learned about Cryptosporidium in water in the last few years. In 1999, the Government introduced new regulations to optimise water treatment and minimising the risk of Cryptosporidium contaminating drinking water. These regulations required water companies to assess each of their water treatment works for risk from Cryptosporidium. From April 2000, the companies were required by law to continuously monitor the effectiveness of the treatment at those sites identified as potentially at risk. Water supplied from these sites has to meet a specific treatment standard for Cryptosporidium. Regulation of Cryptosporidium in drinking water in England and Wales is now the most advanced in the world. DWI experts offer advice guidance on Cryptosporidium internationally.
	Pesticides Traces of pesticides can be found in some drinking water. When found, the levels are very low, are not harmful to health and are usually the result of pesticide usage by farmers, gardeners and highway authorities. Where necessary, water companies have been installing treatment to remove pesticides from drinking water. In 2002, 99.99% of over 850,000 tests carried out met the standard.
	Lead Lead in the environment comes from a variety of sources and may be present in air, food or water. Lead can affect the mental development of children and may also be a factor in behavioural problems. In drinking water it comes mostly from lead pipes that may be in some people's houses.
Where necessary, water companies treat water to prevent it picking up lead from pipes. A leaflet is available which gives advice on how to reduce exposure to lead from drinking water. In 2002, the standard for lead was met in 96.50% of water supply zones compared with 95.44% in 2001. New and more stringent standards have been set for lead. An interim standard has to be met by 2003, and a final standard by 2013. Water companies are now working towards meeting these tighter standards.
	Nitrate Nitrate comes from fertilizers and may find its way into drinking water when it can sometimes be harmful to very young babies. A safety margin built into the drinking water standards for nitrate so that even if it is breached, babies' health is unlikely to be harmed. Water companies have been taking action to control nitrate levels in drinking water. In 2002, the standard for nitrate was met in 99.35% of zones, which is about the same as that achieved in 2001.
	Iron Iron can discolour water and the discolouration is often unacceptable to consumers. Iron occurs naturally in many water sources, but may also be derived from the corrosion of iron mains. Any discolouration of water by iron is unlikely to be harmful to health.
The iron standard was met in 86.60% of water supply zones in 2002. This is better than in 2001 when 85.03% of zones met the standard. The position will improve further as water companies implement major refurbishment programmes in hand to replace or reline corroded mains. These improvement programmes will take a number of years to complete.

What if there is a problem with my water supply?

In the first instance, contact your water company. Enquiry and emergency numbers are listed under Water in your telephone directory. If you are unhappy with the water company's response then:

Contact your local WaterVoice (formerly OFWAT Customer Service Committee) listed under Consumer Organisations in your telephone directory.

OR contact the Environmental Health Department of your local authority.

OR contact the DWI ­ the address is overleaf.

Where can I get more information about drinking water quality?

If you would like more information about drinking water quality you can get it from:

Your water company's public record

You can see the record at one of the company's offices. Customer services staff will explain the result of tests and tell you what is being done to rectify any failures. You are entitled to a free copy of the record for the area in which you live. Alternatively, you can write to the company for details.

Your local authority

Water companies are required to give local authorities information about the quality of water supply in their areas.

Our Annual Reports

These are lengthy reports containing a great deal of detailed information about
the quality of drinking water in England and Wales. They can be bought from The Stationery Office. You may be able to see a copy at a main library or at your water company's offices. You may also view it on the DWI web site: www.dwi.gov.uk

Free leaflets ­ available from DWI (listed below)

­ What do we do?
­ Lead in drinking water
­ Chlorine, smell and taste
­ Problems with your drinking water

­ DWI Reports on each water company

­ Tap water, where does it come from
and how is it made safe to drink?

­ Using lead-free solder for
drinking water fittings

­ Discoloured water
­ Private water supplies
­ Water hardness

 

DRINKING WATER IN ENGLAND AND WALES IS OF A VERY HIGH QUALITY Our job is to make sure it stays that way.

Department for Enviroment,
Food & Rural Affairs (DEFRA)

The National Assembly for Wales /
Cynulliad Cenedlaethol Cymru

Last updated April 2003

Web site terms
© Crown copyright 2002