Index of Contents:
- Introduction
- Coliform Bacteria
- Pesticides
- Lead
- Iron and Manganese
- Cryptosporidium
- Drinking Water Quality Incidents
- Prosecutions
- 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 Yorkshire Water Services 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..
Yorkshire Water continues to supply you with drinking water of a high quality. In 2001, 99.91% of more than 265,000 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, Yorkshire 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 Yorkshire 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, Yorkshire 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. Only one of the Company’s service reservoirs failed the standard. This service reservoir has been de-commissioned. DWI was concerned about failures of total coliform standard at two treatment works. The Company has taken remedial action at both works to prevent a recurrence of the problem.
Coliform bacteria were detected in 0.4% of the water samples taken from consumers’ taps. Many of these failures could be 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
Yorkshire Water carried out more than 82,000 tests for individual pesticides during 2001 and all but 20 samples met the stringent standard. This reflects the significant investment in recent years to remove pesticides from drinking water.
Most of the failures related to one water treatment works, where additional treatment is being installed to remove any pesticides that from time to time might be present in the source water. 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, Yorkshire Water informs the householder of any problems and advises of 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 Yorkshire 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.
Only two of 1,699 samples taken by Yorkshire 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, 49 of the 6,509 samples taken for iron failed the standard. Thirteen of the 6,509 samples taken for manganese failed the standard. This reflects the impact of the renovation programme being carried out by Yorkshire Water to its distribution system. Although parts of the programme were significantly affected by the impact of the Foot and Mouth Disease Outbreak, Yorkshire Water renovated a total of 867 km of mains during 2000 and 2001. The improvement programme, which covers most of the areas affected by the failures, is ongoing with Yorkshire Water being required to rehabilitate a further 4,519 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 Yorkshire Water fulfilled its requirement to carry out continuous sampling and monitoring at ten 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. Yorkshire 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 seven sites. One of these programmes was completed during 2001.
7. Drinking Water Quality Incidents
DWI regarded 12 of the events notified during 2001 by the Company as incidents. The details are shown below.
Nine of the incidents assessed by DWI were of short duration and the Company took remedial action. Ten recommendations were made, mainly regarding procedures. Three incident assessments remain under consideration.
In 2001, DWI also assessed two incidents that occurred in 1999 and seven incidents that occurred in 2000.
8. Prosecutions
Section 70 of the Water Industry Act makes it a criminal offence for a water company to supply water that is unfit for human consumption. DWI investigates all drinking water incidents and will consider prosecuting if it is in the public interest; if there is sufficient evidence that a water company supplied water unfit for human consumption, and if it does not have a defence that it took all reasonable steps to prevent the incident from occurring or failed to exercise due diligence to secure the supply.
At Leeds Crown Court in January 2002, Yorkshire Water pleaded guilty to supplying water unfit for human consumption during an incident that occurred in February 1999, when consumers in Denholme and Thornton received discoloured water. The Company asked for a further offence, involving the supply of discoloured water to consumers in Pudsey in May 1999, to be taken into consideration. The Company was fined a total of £15,000 with costs of more than £8,200 awarded against it.
Formal caution
In August 2001, Yorkshire Water received two formal cautions, which will remain on the files, having admitted supplying water unfit for human consumption contrary to Section 70 of the Water Industry Act 1991. Both related to incidents involving the supply of discoloured water; one to consumers in parts of Pudsey in February 1999 and the other to consumers in the High Storrs area of Sheffield in October 1999.
In January 2002, Yorkshire Water received two further formal cautions, having admitted supplying water unfit for human consumption contrary to Section 70 of the Water Industry Act 1991. Both related to incidents involving the supply of discoloured water; one to consumers in parts of West Leeds in February 1999 and the other to consumers in Holmfirth in March 2000.
Summary of water quality incidents reported in 2001
Type of incident
No.of incidents
Assessment completed
Areas affected
Supply of discoloured water
4
Yes
Bessacar, Doncaster (March); Shadwell, Leeds and Bradford (June); Cottingley (October)
3
No
Sandygate, Sheffield and Sheffield 10 (June); Harrogate (November)
Microbiological contamination of supplies in distribution system
1
Yes
Hornsea (August)
Cryptospiridium oocysts in treated water
1
Yes
Gandale, N Yorkshire (December)
Failure of disinfection systems
1
Yes
East Ness (March)
Other incidents not affecting water quality
2
Yes
Halifax (October); Thwing (December)
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,
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Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi.enquiries@defra.gsi.gov.uk
Published 17 July 2002
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