Index of Contents:
- Introduction
- Coliform Bacteria
- Pesticides
- Lead
- Iron and Manganese
- Cryptosporidium
- Drinking Water Quality Incidents
- 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 United Utilities Water Plc 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..
United Utilities continues to supply you with drinking water of a high quality. In 2001, 99.80% of more than 341,000 tests met the drinking water standards. This is below 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, United Utilities 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 United Utilities 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, United Utilities 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, only three service reservoirs failed the standard. DWI is considering enforcement action to require the Company to make improvements at these service reservoirs.
During 2001, DWI was concerned about failures at three treatment works and is considering enforcement action at these works.
Coliform bacteria were detected in 0.7% 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
United Utilities carried out more than 34,400 tests for individual pesticides during 2001 and all but nine samples met the stringent standard. At the very low concentrations found, the pesticides detected did not represent any risk to health.
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, United Utilities 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 taps.
If you are concerned about the possibility of lead in your drinking water, you should contact United Utilities 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.
Seventy-six of 4,846 samples taken by United Utilities 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, 161 of the 10,102 samples taken for iron failed the standard; 57 of the 10,103 samples taken for manganese failed the standard. This reflects the impact of the programme of work being carried out by United Utilities to renovate its distribution system. During 2000 and 2001, the Company renovated 1,409 km of water mains. The improvement programme, which covers most of the areas affected by the failures, is ongoing with United Utilities required to renovate a further 6,280 km of mains by 2010.
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, United Utilities fulfilled its requirement to carry out continuous sampling and monitoring at nine 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. United Utilities reported no failures during 2001.
7. Drinking Water Quality Incidents
DWI regarded 18 of the events notified during 2001 by United Utilities as incidents. The details are shown below.
Each of the incidents assessed by DWI were of short duration and United Utilities took remedial action. Eighteen recommendations were made mainly regarding operations.
Summary of water quality incidents reported in 2001
Type of incident
No.of incidents
Assessment completed
Areas affected
Supply of discoloured water
13
Yes
Wirral (February, July, September); Wigan (March); Liscard (March); Macclesfield (April); Stalybridge (April); Winsford (April); Huntington WTW (July); Glossop (August); Hyde (August); Chorley (November); Bootle (November)
Supply of water with taste & odour
2
Yes
Hoghton WTW (February); Rainhill (August)
Loss of supplies
2
Yes
Macclesfield (December); Embleton (December)
Wholesomeness concerns
1
Yes
Hurleston WTW (May)
9. 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:
What do we do?
How good is the drinking water?
Problems with your drinking water
Chlorine, smell and taste
Discoloured water
Lead in drinking water
Private water supplies
Water hardness
Tap water, where does it come from and how is it made safe to drink?
Using lead-free solder for drinking water fittings
DWI reports on each water company
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Drinking Water Inspectorate,
Floor 2/A1, Ashdown House, 123 Victoria Street, London, SW1E 6DE
Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi.enquiries@defra.gsi.gov.uk
Published 10 July 2002
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