HC Deb 10 March 1997 vol 292 cc74-6W
Mr. Boateng

To ask the Secretary of State for the Environment how many incidents of cryptosporidum in the water supply have been notified to him in the past 12 months; and in which water company areas. [18911]

Mr. Clappison

Water companies in England and Wales are required to report all incidents in which drinking water quality might be affected. All incidents are investigated by the drinking water inspectorate. Most incidents are relatively minor happenings.

The most significant risk to drinking water quality is the presence of cryptosporidium oocysts. On cryptosporidium, the notification to the inspectorate can relate either to the detection of cryptosporidium oocysts in treated water or to an increase of the illness cryptosporidiosis in the community or both. The transmission of the illness occurs in a number of ways and often through contact with animals. One recent outbreak of cryptosporidiosis was found to be associated with the failure of a milk pasteurisation plant.

All incidents are investigated fully by the inspectorate. As cryptosporidiosis can be transmitted in many ways, the source of any outbreak has to be established through epidemiology. A case of South West Water Services Ltd. allegedly supplying water unfit for human consumption during 1995 because of cryptosporidium is currently before the courts.

Notifications of events involving cryptosporidium since 1 March 1996 are listed below under three headings, with the status of the investigation. It should be noted that not all notifications become confirmed as incidents.

Cryptosporidium oocysts detected in treated water but no reported increase of cryptosporidiosis in the community
Water company area Date Location Status
South West Water 29 May 1996 Littlehempston Concluded
Cambridge Water 30 May 1996 Duxford/Linton Concluded
South West Water 27 June 1996 Crown Hill WTW Concluded
Mid Kent Water 3 July 1996 Burham WTW Concluded
Southern Water
Yorkshire Water 17 October 1996 Elvington WTW (raw water only) Under investigation
Northumbrian Water 22 October 1996 Lumley WTW Under investigation
Yorkshire Water 21 February 1997 Pately Bridge Under Investigation
An increase in cryptosporidiosis in the community but oocysts not detected in treated water
Water company area Date Location Status
Yorkshire Water 21 March 1996 Tophill Low Under investigation
Anglian Water 12 February 1997 Bedford area Under investigation
Three Valleys Water 26 February 1997 Luton/Dunstable Under investigation
Both oocysts detected in treated water and an increase of cryptosporidiosis in the community
Water company area Date Location Status
North West Water 29 April 1996 The Wirral Under investigation
Portsmouth Water 18 November 1996 Itchen WTW Under investigation
Three Valleys Water 2 March 1997 Clay Lane WTW Under investigation