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Summary Report for 2001 on
Severn Trent Water Limited

Index of Contents:

  1. Introduction
  2. Coliform Bacteria
  3. Pesticides
  4. Lead
  5. Iron and Manganese
  6. Cryptosporidium
  7. Drinking Water Quality Incidents
  8. Further Information

1. Introduction

The Drinking Water Inspectorate (DWI) checks on behalf of the Government that water companies supply water that is safe to drink. This leaflet summarises the results of our checks on Severn Trent Water Limited during 2001. You should read it alongside DWI’s leaflet, How Good is the Drinking Water? which gives more details on the standards and tests. This is available free of charge and on the DWI web site at www.dwi.gov.uk..

Severn Trent Water continues to supply you with drinking water of a high quality. In 2001, 99.91% of more than 273,900 tests met the drinking water standards. This is above the overall figure for England and Wales of 99.86%. The tests are carried out on samples taken from water treatment works, service reservoirs and consumers’ taps.

None of the failures of the standards in 2001 were considered harmful to consumers’ health. Each failure was assessed and, where necessary, Severn Trent Water has taken action to prevent further failures.

Although the 2001 results are good, there are some matters, which may concern you. These are detailed below including any steps taken by Severn Trent Water to further improve its performance.

2. Coliform bacteria

Occasionally, coliform bacteria may be found in drinking water samples; these are not considered harmful to consumers’ health. If coliform bacteria are detected, Severn Trent Water investigates immediately.

During 2001, low numbers of coliform bacteria were detected in the water leaving a small number of water treatment works and service reservoirs. The standard at service reservoirs permits 5% of samples to contain coliform bacteria and, in 2001, none of the Company’s service reservoirs failed the standard.

During 2001, DWI was concerned about failures at one treatment works and is considering enforcement action to require the company to make improvements at the works to prevent failures from recurring.

Coliform bacteria were detected in 0.4% of the water samples taken from consumers’ taps. Many of these failures may have been due to the condition of the tap and not the water itself. The standard permits 5% of samples in a water supply zone to contain coliform bacteria and all zones met the standard.

3. Pesticides

Severn Trent Water carried out more than 48,800 tests for individual pesticides during 2001. All samples met the stringent standard, reflecting the significant investment in recent years to remove pesticides from drinking water.

4. Lead

Samples do occasionally fail the standard for lead, even where additional treatment has been installed to reduce the amount of lead picked up by water from pipework. These failures are usually due to the consumers’ water pipes being made of lead. Whenever a failure occurs, Severn Trent Water informs the householder of any problems and advises of any action that can be taken to reduce lead levels in the water at their kitchen tap.

If you are concerned about the possibility of lead in your drinking water, you should contact Severn Trent Water to see whether there is a problem. A leaflet about lead in drinking water is available from DWI free of charge and can also be found on the DWI web site.

Three of 665 samples taken by Severn Trent Water failed the standard for lead during 2001.

5. Iron and manganese

These two parameters provide a good indication of the overall condition of the mains used to distribute drinking water throughout the area of supply.

During 2001, only 35 of 5,390 samples taken for iron failed the standard. Only one of 1,531 samples taken for manganese failed the standard. This reflects the impact of the renovation programme being carried out by Severn Trent Water to its distribution system. During 2000 and 2001, the Company renovated 886 km of water mains. This programme, covers most of the areas affected by the failures, and is ongoing as Severn Trent Water is required to renovate a further 1,010 km of mains by 2003.

6. Cryptosporidium

Cryptosporidium is a tiny micro-organism that can sometimes cause a form of diarrhoea called cryptosporidiosis. There are a number of sources of Cryptosporidium other than drinking water, New regulations require water companies to sample continuously and analyse daily for Cryptosporidium in the treated water at potentially vulnerable sites.

It is a criminal offence to exceed the new treatment standard for Cryptosporidium.

During 2001, Severn Trent Water fulfilled its requirement to carry out continuous sampling and monitoring at eight of its sites that were identified as being at significant risk from Cryptosporidium. The Company is required to tell DWI of any failures to meet the treatment standard. SevernTrent Water reported no failures during 2001

In addition, as part of the new regulations, the Company is committed to programmes of work to reduce any potential risk from Cryptosporidium at 20 sites. Ten of these programmes were completed during 2001.

7. Drinking Water Quality Incidents

DWI regarded five of the events notified during 2001 by Severn Trent Water as incidents. The details are shown in the table below.

Four of the incidents assessed by DWI were of short duration and the Company has taken appropriate remedial action. Two recommendations were made mainly regarding delays in sampling and analysis.

Also in 2001, DWI assessed five incidents that occurred in 2000.

Summary of water quality incidents reported in 2001


Type of incident


No.of incidents


Assessment completed


Areas affected

Supply of discoloured water

2

Yes

Stafford (June) and Droitwich (April)

 

1

No

Gloucester (August

Microbiological contamination

2

Yes

Stroud (July) and Stourbridge (August)

8. Further information

If you would like more information about drinking water quality the following leaflets are available free of charge from DWI and can also be found on the DWI web site:

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Drinking Water Inspectorate,
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Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi.enquiries@defra.gsi.gov.uk

Published 10 July 2002
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