Archive:
(for archive/historical purposes, this document has not been updated)Index of Contents:
- Introduction
- Bacteria
- Pesticides
- Lead
- Iron and Manganese
- Cryptosporidium
- Drinking Water Quality Incidents
- Determinations in 1998
1. Introduction
The Drinking Water Inspectorate (DWI) checks that water companies supply water that is safe to drink when it reaches your home. This leaflet summarises the results of our checks on Portsmouth Water plc during 1998. and should be read in conjunction with DWI's "How Good is the Drinking Water ?" leaflet which is available from us free of charge.
Portsmouth Water continues to supply you with drinking water of a very high quality. The number of results not meeting the standards has fallen consistently since 1991 and in 1998, 99.89% of more than 26,700 tests met the standards. This is above the overall figure for England and Wales of 99.78%.
None of the failures in 1998 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 1998 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 improve its performance.
2. Bacteria
Whenever bacteria are found in water samples Portsmouth Water investigates immediately.
Occasionally low numbers of bacteria were detected in the water leaving a small number of water treatment works during 1998. The bacteria found were not harmful to consumers' health. One service reservoir failed to meet the required standard for coliforms but the failure is not considered significant. 10 out of 3,700 tests at consumers' taps contained bacteria. These failures may be due to the condition of the tap and not the water itself.
3. Pesticides
Portsmouth Water carried out more than 1,000 tests for individual pesticides during 1998 and all bar one met the stringent standard.
4. Lead
Only one of the samples taken by Portsmouth Water failed the standard for lead, and this was in an area where additional treatment is being installed to reduce the amount of lead picked up by water from pipework. The householder was informed of the problem. 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 from us free of charge.
5. Iron and Manganese and polycyclic aromatic hydrocarbons (PAH)
These three parameters provide a good indication of the overall condition of the mains used to distribute drinking water through the region.
None of the samples taken for iron or manganese, during 1998, failed the standards. The number of samples failing to meet the standard for PAH was not considered significant.
6. Cryptosporidium
Cryptosporidium is a tiny micro-organism which can sometimes cause a form of diarrhoea called cryptosporidiosis. No instances were reported to the Inspectorate of the detection of cryptosporidium in water leaving Portsmouth Water’s water treatment works during 1998.
Water companies will shortly be required to sample continuously and analyse daily for cryptosporidium in the treated water at theirtheir most vulnerable sites. It will be an offence if they fail to meet a new treatment standard.
7. Drinking Water Quality Incidents
In December 1998 the disinfection system at one of the Company’s treatment works failed and the Company issued advice to boil water to about 100,000 consumers.
8. Determinations in 1998
Parameter
Total
Contravening PCV No % Coliforms 1881 9 0.5 Faecal coliforms 1881 1 0.1 Colour 219 0 0.0 Turbidity 377 0 0.0 Odour 363 0 0.0 Taste 362 0 0.0 Hydrogen ion 1837 0 0.0 Nitrate 423 0 0.0 Nitrite 428 0 0.0 Aluminium 174 0 0.0 Iron 102 0 0.0 Manganese 113 0 0.0 Lead 163 1 0.6 PAH 106 7 6.6 Trihalomethanes 95 0 0.0 Total pesticides 152 0 0.0 Diuron 46 1 2.2 Other pesticides 959 0 0.0 Benzo 3,4 pyrene 106 0 0.0 All others 6103 0 0 Total
15890 19 0.1
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Drinking Water Inspectorate,
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Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
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Updated 11 July 2001
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