Last update:

11th July 2007

Quick links:

How is water quality measured

Who ensures drinking water meets standards

Drinking water supply in the South West

Drinking water quality in the South West

Drinking water quality in England

European & worldwide perspective

Drinking water quantity

South West water companies

Pollution incidents

Estuaries

Groundwater

Water resources

Rivers

Abstractions

Useful websites:

Drinking Waters Inspectorate

Bournemouth & West Hampshire Water

Bristol Water

Ofwat

Severn Trent plc

South West Water

Thames Water

Wessex Water

European Research on Water Directive

Drinking Water

What's new on this page...

• Drinking Water quality 2006
• State of the South West's Environment 2006 summary - inland water chapter

In the South West, drinking water is supplied by Bournemouth & West Hampshire Water, Bristol Water, Cholderton & District Water, South West Water, Wessex Water and some parts by Thames Water and Severn Trent Water (see page on water suppliers for maps).

These water companies supply a population of 19,522,000 through 111,997 km of mains.

How is water quality measured?

The Government has set legal standards for drinking water in the Water Quality Regulations (based on World Health Organisation guidelines). The UK also has additional standards to safeguard the already high quality of water in England and Wales. These standards cover:

• Bacteria
• Chemicals such as nitrate and pesticides
• Metals such as lead
• Look and taste

Drinking water quality is measured in zones containing no more than 100,000 consumers. Calculating the mean zonal compliance % for forty parameters gives a broad measure of overall compliance by water companies with European and national drinking water standards.

Who ensures drinking water meets these standards?

The Drinking Water Inspectorate (DWI) carries carries out inspections, which includes checks to ensure that:

• Sampling procedures are satisfactory
• Samples are tested by trained staff using accurate methods
• The right numbers of tests are carried out
• Correct results are entered in the public record
• Appropriate water treatment processes are used
• Treatment processes and the water distribution system are operated and maintained with safety in mind
• Consumers receive sound advice and help with queries and concerns

Detailed assessments of every failure to meet standards are made and the Drinking Water Inspectorate has a duty to ensure water companies take appropriate action as well as check that improvements are completed on time.

Drinking water supply in the South West

The 2006 Drinking Water Quality report was published in June 2007. The Western region report analyses six water companies supply drinking water in the Western Region: Bournemouth and West Hampshire Water, Bristol Water, Cholderton and District Water, South West Water, Wessex Water and Thames Water (which covers an area around Tidworth). See map of water company areas for more information).

Overall, drinking water quality remained of good quality throughout the year. The region exhibited a small incremental improvement in the index used by the Inspectorate to describe overall compliance with drinking water standards at consumers’ taps (40 parameters). The figure for 2006 was 99.96% compared to 99.95% in 2005 and 99.92% in 2004.

Much of the water in the region is derived from surface water (67%) abstracted from rivers such as the Avon (Hampshire), Dart, Exe, Fowey, Stour and Tamar. The upland areas of Bodmin, Dartmoor, Exmoor and Mendip are important catchments for water resources in the region. Surface water is drawn from many reservoirs including Clatworthy, Colliford, Roadford and Wimbleball.

Groundwater provides a quarter of the region’s water resources. Many boreholes draw water from the chalk aquifer of the Wessex basin, but the Permian and Triassic sandstone aquifer in the Otter Valley is also an
important groundwater source. Cholderton and District Water, the smallest public water supply company in England, relies exclusively on the chalk aquifer of the Wessex basin. Across the region a small proportion of water supplies (8%) are a mixture of surface and groundwater sources.

key facts

Source: Drinking Water Inspectorate (2007)

Drinking water quality in the South West

Throughout 2006, water companies sampled drinking water across the region to test for compliance with the standards in the Water Supply (Water Quality) Regulations 2000. More than one-third of the tests were carried out on drinking water drawn from consumers’ taps selected at random. Other sample locations are water treatment works and treated water (service) reservoirs.

Collectively, the six water companies carried out a total of 654,613 tests during 2006 - only 164 (0.02%) of these tests failed to meet the standards set down in the regulations.

Drinking water quality summary

NB. Industry average for overall drinking water quality in both 2005 and 2006 was 99.96%.

Detailed individual company results can be downloaded here.

Source: Drinking Water Inspectorate (2007)

Useful links

Click here for more information about water suppliers and useful weblinks about water regulation, suppliers, background information and the independant Consumer Council for Water.

The Consumer Council for Water was set up in 2005 to provide a strong voice for water and sewerage consumers in England and Wales. With offices throughout both countries, we keep in close contact with companies that provide the services as well as the consumer themselves.

Drinking water quality in England

There was a slight increase in compliance with drinking water standards in England between 2004 (99.94%) and 2005 (99.96%). As a whole therefore the picture for 2005 is one of improvement from the baseline set in 2004 (the first year of reporting against the new standards).

Drinking Water Quantity

The volume of drinking water abstracted from the environment and supplied to various users is described in a abstractions and demand for water.

European and worldwide perspective

Mismanagement, limited resources and environmental changes mean that almost one-fifth of the planet's population still lacks access to safe drinking water (UNESCO, 2006)

In Western Europe, 15% of the population have bad drinking water that is contaminated by bacteria. This problem increases to around 30% in Eastern Europe (European Environment Agency, 2005).