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 Dee Valley 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..
Dee Valley Water continues to supply you with drinking water of a high quality. In 2001, 99.88% of more than 13,000 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, Dee Valley 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 Dee Valley 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, Dee Valley Water investigates immediately.
During 2001, no coliform bacteria were detected in the water leaving any of the company’s water treatment works. Low numbers were detected in water leaving a single service reservoir. The standard at service reservoirs permits 5% of samples to contain coliform bacteria and the service reservoir met the standard.
None of the water samples taken from consumers’ taps contained coliform bacteria.
3. Pesticides
Dee Valley Water carried out more than 1,500 tests for individual pesticides during 2001 and all samples met the stringent standard.
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.
If you are concerned about the possibility of lead in your drinking water, you should contact Dee Valley Water to see if 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.
No samples taken by Dee Valley 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, one of the 239 samples taken for iron failed the standard. Three of 172 samples taken for manganese failed the standard. This reflects the impact of the renovation programme being carried out by Dee Valley Water to its distribution system.
During 2000 and 2001, the Company renovated 40 km of water mains. The programme, covers most of the areas affected by the failures, and is ongoing with Dee Valley Water required to renovate a further 76 km of mains by 2004.
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, Dee Valley Water fulfilled its requirement to carry out continuous sampling and monitoring at two 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. Dee Valley Water reported no failures during 2001.
7. Drinking Water Quality Incidents
DWI regarded one event notified during 2001 by Dee Valley Water as an incident. The details are shown below.
The incident, assessed by DWI, was of short duration and Dee Valley Water took remedial action. Five recommendations were made to the Company 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
1
Yes
Borras (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:
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,
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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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