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 Northumbrian 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..
Northumbrian Water continues to supply you with drinking water of a high quality. In 2001, 99.91% of more than 206,900 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, Northumbrian 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 Northumbrian 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, Northumbrian 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 none of the Company’s service reservoirs failed the standard.
Coliform bacteria were detected in 0.5% 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. This is similar to last year’s result.
3. Pesticides
Northumbrian Water carried out more than 89,300 tests for individual pesticides during 2001, all but 23 samples met the stringent standard. At the very low concentrations found, the pesticides detected did not represent any risk to health. This reflects the significant investment in recent years to remove pesticides from drinking water. However, additional treatment is being installed to remove any pesticides, which from time to time might be present in the source 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, the householder is informed of any problems by Northumbrian Water and advised 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 Northumbrian 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.
Twelve samples from 1,716 taken by Northumbrian 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, 46 of 3,481 samples taken for iron failed the standard. Eight of 3,481 samples taken for manganese failed the standard. This reflects the impact of the renovation programme being carried out by Northumbrian Water to its distribution system.
Northumbrian Water renovated a total of 732km of mains during 2000 and 2001. This programme, covers most of the areas affected by the failures, and is ongoing with Northumbrian required to renovate a further 3,900km 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, Northumbrian Water fulfilled its requirement to carry out continuous sampling and monitoring at nine of its sites that were identified as being at significant risk from Cryptopsoridium. The Company is required to tell DWI of any failures to meet the treatment standard. Northumbrian Water reported no failures during 2001.
As part of the new regulations, the Company is committed to programmes of work to reduce any potential risk from Cryptosporidium at 11 sites. Five of these programmes were completed during 2001.
7. Drinking Water Quality Incidents
DWI regarded 21 of the events notified during 2001 by the Company as incidents. The details of these are shown below.
Nineteen of the incidents, assessed by DWI, were of short duration and the Company took remedial action. Six recommendations were made mainly regarding operations and sampling. One incident from 2001 remains under consideration.
In 2001, DWI also assessed three 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
15
Yes
Wallsend (January), Fulwell (March), Yarm (April), Wallsend (April), Berwick (April), Fawdon (May), Darlington (June), Prudhoe (July), Middlesbrough (July), Cramlington (August), Gateshead (August), Billingham (August), Darlington (September), Eaglescliffe (October), Newcastle (November)
1
No
Fontburn (August)
Disinfection failure
1
Yes
Murton (June)
Boil water advice
2
Yes
West Denton (July); Halton Le Gate (September)
Vandalism
1
Yes
Rainten (October)
Pesticide breaches
1
Yes
Tyneside (December
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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