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 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 Northumbrian 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.
Northumbrian Water continues to supply you with drinking water of a high quality. In 1998, 99.78% of more than 176,200 tests met the standards. This is identical to 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 Northumbrian 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 Northumbrian Water to improve its performance.
2. Bacteria
Whenever bacteria are found in water samples Northumbrian Water investigates immediately.
Low numbers of bacteria were detected in the water leaving an increased number of water treatment works during 1998. There was also an increase in the number of contravention of microbiological standards at service reservoirs. The number of bacteriological failures at consumers' taps was 0.8% of the samples taken. Many of these failures may be due to the condition of the tap and not the water itself. All the contraventions of the microbiological standards were considered not significantl or unlikely to recur, except that the Inspectorate considered enforcement action was necessary for improvements to be made at two works and to supplies to one zone. The bacteria found were not harmful to consumers' health.
3. Pesticides
Northumbrian Water carried out more than 57,500 tests for individual pesticides during 1998 and all except two met the stringent standard. This reflects the significant investment in recent years to install treatment to remove pesticides from drinking water. The Inspectorate considered both contraventions were not significant or unlikely to recur.
4. Lead
Northumbrian Water had 25 samples of 1,766 taken fail the standard for lead. The Company is taking action to comply with the lead standard and has given an Undertaking to install additional treatment facilities. 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 zones failing the standard for manganese, iron and PAH was similar to 1997. A significant programme of work is being carried out by Northumbrian Water to renovate its distribution system. The programme of improvement is ongoing, with Northumbrian Water being required to renovate more than 4,683km of mains by 2010.
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 Northumbrian 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
During 1998 13 incidents in which drinking water quality deteriorated were reported to the Inspectorate. The Inspectorate has investigated or will investigate and report on each incident.
Eleven of the 13 incidents were associated with the supply of discoloured water. Six discolouration incidents in Ashington, North Shields, Holystone, Redcar and two in Gosforth Park, followed planned work on the distribution system by the Company; a further five discolouration incidents were associated with burst mains in South Shields, Chester-le-Street, Billingham and two in Wallsend. Of the remaining two incidents, one was associated with a deterioration in raw water quality entering Horsley Water Treatment Works and the other involved the detection of coliforms in the treated water leaving Birchtrees Water Treatment Works.
8. Prosecutions
In September 1997 discoloured water was supplied to the Ashington area after Northumbrian Water had made operational changes to its distribution system. On 5 October 1998 at Bedlington Magistrates Court, the Company admitted supplying water unfit for human consumption to premises in Ashington. The Company was fined a total of £6,000 and ordered to pay £3,776 towards prosecution costs.
9. Determinations in 1998
Parameter
Total
Contravening PCV No % Coliforms 7522 58 0.8 Faecal coliforms 7522 6 0.1 Colour 7522 5 0.1 Turbidity 7522 13 0.2 Odour 873 0 0.0 Taste 911 2 0.2 Hydrogen ion 7522 0 0.0 Nitrate 984 0 0.0 Nitrite 984 0 0.0 Aluminium 3529 7 0.2 Iron 3529 67 1.9 Manganese 3529 55 1.6 Lead 1766 25 1.4 PAH 533 3 0.6 Trihalomethanes 529 16 3.0 Total pesticides 1021 0 0.0 Chlorotoluron 987 1 0.1 Diuron 987 1 0.1 MCPA 998 0 0.0 Mecoprop 998 0 0.0 Simazine 1013 0 0.0 Other pesticides 52549 0 0.0 Benzon-3,4-pyrene 533 1 0.2 All others 21089 0 0.0 Total
134952
260
0.2
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Drinking Water Inspectorate,
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Updated 11 July 2001
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