Archive:
(for archive/historical purposes, these documents have not been updated)Index of Contents:
- Introduction
- Bacteria
- Lead
- Iron and Manganese
- Cryptosporidium
- Drinking Water Quality Incidents
- Determinations in 1999
1. Introduction
The Drinking Water Inspectorate (DWI) checks that water companies supply water that is safe to drink when it reaches your home. This document summarises the results of our checks on Portsmouth Water plc during 1999 and should be read in conjunction with DWI's "How Good is the Drinking Water?" leaflet which is available here and also from us free of charge from the address at the end of this document.
Portsmouth Water continues to supply you with drinking water of a high quality. In 1999, 99.83% of more than 26,300 tests met the standards. This is close to the overall figure for England and Wales of 99.82%.
None of the failures in 1999 were likely to harm consumers' health. We assessed each one and, where necessary, we have required Portsmouth Water to take action to prevent further failures.
Although the 1999 results are good, we know that there are some matters of everyday concern to consumers. These are detailed below including the steps taken by Portsmouth Water to further improve its performance.
2. Bacteria
Whenever bacteria are found in water samples Portsmouth Water investigates immediately. Occassionally low numbers of bacteria were detected in the water leaving a small number of treatment works and service reservoirs during 1999. The bacteria found were not harmful to consumers health. Bacteria were detected in 0.5% of water samples from consumers' taps. Many of these could be due to the condition of the tap and not the water itself.
3. Lead
Samples 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. In many cases this is due to the consumer's water pipes being made of lead. None of the 195 samples taken by Portsmouth failed to meet the standard for lead. The Drinking Water Inspectorate advises consumers living in properties with lead pipes to seek advice from their water company. A DWI leaflet about lead in drinking water is also available here and from us free of charge from the address at the end of this document.
4. Iron and Manganese
These parameters provide a good indication of the overall condition of the mains used to distribute drinking water through the region.
Only one sample taken by Portsmouth Water failed to meet the standards for iron and no samples failed the standard for manganese during 1999.
5. 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 water but due to new regulations water companies are now required by law to sample continuously and analyse daily for Cryptosporidium in the treated water at those sites which have a potential vulnerability. All water companies had to initially conduct risk assessments at their sites to identify if there was any significant risk of contamination. Portsmouth Water identified that there was significant risk at six of its sites and it is now continuously sampling and monitoring the treated water at these sites. At all these sites, the Company is required to ensure adequate treatment is in place and it is an offence if the new treatment standard for Cryptosporidium is exceeded. In addition to the regulatory requirement, the Company is able to get early warning of any treatment problems from this monitoring system.
6. Drinking Water Quality Incidents
Four incidents were reported to the Inspectorate, two involved the supply of water with an earthy taste, one involved consumer complaints of a creosote type taste and one involved an increased incidence of cryptosporidiosis in the community.
7. Determinations in 1999
Parameter
Total
Contravening PCV No % Coliforms 1872 9 0.5 Faecal coliforms 1872 2 0.1 Colour 242 0 0.0 Turbidity 379 1 0.3 Odour 356 0 0.0 Taste 359 0 0.0 Hydrogen ion 1732 0 0.0 Nitrate 425 0 0.0 Nitrite 425 0 0.0 Aluminium 152 0 0.0 Iron 126 1 0.8 Manganese 102 0 0.0 Lead 195 0 0.0 PAH 105 8 7.6 Trihalomethanes 93 0 0.0 Total pesticides 142 0 0.0 Diuron 45 0 0.0 Other pesticides 880 0 0.0 Benzo-3,4-pyrene 105 1 1.0 All others 6285 0 0.0 Total 15892 22 0.1
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Drinking Water Inspectorate,
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Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi_enquiries@detr.gov.uk
Published 12 July 2000 / Updated 11 July 2001
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