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
- Prosecutions
- 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 Anglian Water Services 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.
Anglian Water continues to supply you with drinking water of a high quality. In 1998, 99.63% of more than 237,500 tests met the standards. This is below 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 Anglian 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 Anglian Water to improve its performance.
2. Bacteria
Whenever bacteria are found in water samples Anglian 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 total coliforms and the Company has taken remedial action to prevent recurrence of the failure. A little over 0.1% of samples taken at consumers’ taps failed to meet the standard. Many of these failures may be due to the condition of the tap and not the water itself.
3. Pesticides
Anglian Water carried out more than 38,000 tests for individual pesticides during 1998 and all met the stringent standard. This reflects the significant investment in recent years to install treatment to remove pesticides from drinking water.
4. Lead
Anglian Water continues to have samples occasionally failing the standard for lead, even where additional treatment has been installed to reduce the amount of lead picked up by water from pipework. In all cases the householder has been 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.
The number of samples failing the standard for iron has fallen consistently since 1995. This overall improvement reflects the impact of the programme of work being carried out by Anglian Water to renovate its distribution system. The number of samples failing the standards for manganese and PAH have remained about the same over the same period. The programme of improvement is ongoing, with Anglian Water being required to renovate more than 893 km of mains by 2002.
6. Cryptosporidium
Cryptosporidium is a tiny micro-organism which can sometimes cause a form of diarrhoea called cryptosporidiosis. In May apparent detection of Cryptosporidium oocysts in water supplied from Marham treatment works was reported to the Inspectorate. Additional tests showed that the detections were false. No other instances were reported to the Inspectorate of the detection of Cryptosporidium in water leaving Anglian 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
The Company reported ten incidents during 1998 in which drinking water quality demonstrably deteriorated, including the detection of presumptive cryptosporidium oocysts mentioned above.
Two involved bacteriological failures due to problems at Bow Brickhill service reservoir in May and at Boothby Graffoe in November. One involved loss of supplies following a power failure at Harpswell and one involved failure of treatment plant at Waddingham, both in September. Five involved discolouration of supplies: one following a burst main at Coggleshall in June; one following restoration of flow after drain down of a water tower caused by a faulty electrical equipment at Felixstowe in September; and three following work on the distribution system, at Ingham in June, at Duston in July, and at Grimsby and Cleethorpes in October.
The Company has carried out reviews of various procedures as the result of recommendations made by the Inspectorate.
8. Prosecutions
As a result of mains renovation in November 1997 a small number of properties in Ipswich were connected to a main carrying untreated river water. It was not until December 1997 that the error was discovered, and normal supplies resumed. Illness was reported in some consumers drinking the water. In 1998, the Company admitted in court supplying water unfit for human consumption and was fined a total of £15,000 and ordered to pay £5,521 towards prosecution costs.
Disturbance of deposits in the mains in the Halstead area in December 1997 due to increased water flows resulted in discolouration of supplies. In 5 January 1999 at Witham Magistrates Court, the Company admitted supplying water unfit for human consumption and was fined a total of £10,000 and ordered to pay £4,886 towards prosecution costs.
9. Determinations in 1998
Parameter
Total
Contravening PCV No % Coliforms 14245 34 0.2 Faecal coliforms 14245 1 < 0.1 Colour 2260 0 0.0 Turbidity 8751 11 0.1 Odour 929 0 0.0 Taste 929 0 0.0 Hydrogen ion 8636 0 0.0 Nitrate 4925 0 0.0 Nitrite 6573 697 10.6 Aluminium 2396 0 0.0 Iron 6924 55 0.8 Manganese 4804 6 0.1 Lead 1331 4 0.3 PAH 609 31 5.1 Trihalomethanes 753 0 0.0 Total pesticides 2517 0 0.0 Atrazine 2041 0 0.0 Bentazone 1884 0 0.0 Isoproturon 1841 0 0.0 Simazine 2041 0 0.0 Other pesticides 30240 0 0.0 Faecal streptococci 1 0 0.0 Nickel 200 1 0.5 Potassium 1381 0 0.0 Sulphate 315 0 0.0 Temperature 13956 0 0.0 All others 31210 0 0.0 Total 165937 840 0.5
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Drinking Water Inspectorate,
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Updated 11 July 2001
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