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 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 North Surrey Water Limited 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.
North Surrey Water continues to supply you with drinking water of a high quality. The number of results not meeting the standards has fallen consistently since 1991 and during 1998, 99.89% of more than 13,100 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 North Surrey 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 North Surrey Water to improve its performance.
2. Bacteria
Whenever bacteria are found in water samples North Surrey Water investigates immediately.
Low numbers of bacteria were detected in the water leaving one water treatment works during 1998. The bacteria found were not harmful to consumers' health. The Inspectorate was concerned about the failures and has required the Company to take action to rectify matters. Low numbers of bacteria were also found at eight service reservoirs, a significant increase since 1996. The Inspectorate considers that these failures are unlikely to recur. The number of bacteriological failures at consumers' taps has fallen slightly from three in 1997 to a single failure in 1998. The failure may have been due to the condition of the tap and not the water itself.
3. Pesticides
North Surrey Water carried out more than 3,500 tests for individual pesticides during 1998 and all met the very stringent standard. This reflects the significant investment in recent years to install treatment to remove pesticides from drinking water.
4. Lead
None of the samples taken by North Surrey Water failed 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 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.
A single sample failed the standard for iron in 1998 and this was considered by the Inspectorate to be not significant. No samples failed the standards for manganese or PAH during 1998. This improvement over recent years reflects the impact of the programme of work being carried out by North Surrey Water to renovate its distribution system which is ongoing, the Company being required to renovate more than 179km of mains by the end of 2006.
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 North Surrey 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 their most vulnerable sites. It will be an offence if they fail to meet a new treatment standard.
7. Drinking Water Quality Incidents
No incidents were reported by the Company to the Inspectorate in 1998.
8. Determinations in 1998
Parameter
Total
Contravening PCV No % Coliforms 1292 1 0.1 Faecal coliforms 1292 0 0.0 Colour 135 0 0.0 Turbidity 141 0 0.0 Odour 209 0 0.0 Taste 209 0 0.0 Hydrogen ion 697 0 0.0 Nitrate 136 0 0.0 Nitrite 135 0 0.0 Aluminium 137 0 0.0 Iron 162 1 0.6 Manganese 136 0 0.0 Lead 56 0 0.0 PAH 62 0 0.0 Trihalomethanes 91 0 0.0 Total pesticides 235 0 0.0 Carbetamide 0 0 0.0 Diuron 145 0 0.0 Isoproturon 144 0 0.0 Linuron 144 0 0.0 Mecoprop 169 0 0.0 Other pesticides 2000 0 0.0 All others 958 0 0.0 Total
8685
2
< 0.1
[ Previous ] [ Contents ] [ Next ]
| A - Z Index | Business and Technical | Consumer Information | Contacting us |
| DWI Home Page | News | Product Approval | Search our site | Wales |
Drinking Water Inspectorate,
Floor 2/A1, Ashdown House, 123 Victoria Street, London, SW1E 6DE
Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi_enquiries@detr.gov.uk
Updated 11 July 2001
Return to Publications and Reports Index
Return to Drinking Water Inspectorate Home Page
Department for Environment, Food & Rural Affairs (DEFRA)Home Page
The National Assembly for Wales / Cynulliad Cenedlaethol Cymru Home Page
Web site terms
© Crown copyright 2001