Company’s £300 million cure for water sickness bug

Date: Saturday 22nd April 2000

NORTH West Water is attempting to eliminate the risk of potentially harmful bacteria leaking into drinking water by spending £300 million to introduce a program of improvements at its reservoirs, including Haweswater and Thirlmere.

It follows the publication of a report which concluded that Thirlmere was “strongly associated” with almost 300 cases of sickness in Lancashire and Greater Manchester last year.

A livestock parasite in drinking water supplied from Thirlmere was one of the most likely causes of the outbreak, according to the study carried out at the North West’s communicable disease surveillance centre in Liverpool.

Lancashire and Greater Manchester health authorities confirmed 282 cases of cryptosporidiosis in April and May last year. The majority of people affected by the illness recovered within two weeks.

Diarrhoea is the main symptom, although nausea, vomiting, fever and headaches can also be caused.

Professor Paul Hunter, who led the investigation, said it was an unpleasant disease. “Steps have been taken by North West Water to remedy the situation and we must now wait and see if they have worked. There is still a great deal of work to be done.”

Experts say the bug can be excreted by livestock or other animals, and it may then be washed by rain into rivers and streams, and then reservoirs.

Last year’s outbreak followed the extraction of an unusually high number of cryptosporidium bug traces from one sample taken from the inlet of the Dunmail Raise treatment works at Thirlmere.

However, no further traces were found in further North West Water tests at Thirlmere, which supplies 620,000 properties in areas of South Cumbria, Lancashire and Greater Manchester.

“The risk of catching cryptosporidiosis in the UK is extremely small,” said Dr. Paul West, NWW’s head of quality regulation. “But, as we learn more about this bug, we recognise that it can pose a risk to water supplies, particularly those drawn from rural reservoirs such as Thirlmere.”


He added that technology used to locate the bug had not even been invented when the outbreak occurred.

Already, the company has installed a sophisticated monitoring system to detect the bug, which prevents organism concentrations forming. A survey to identify water sources at risk is underway and grazing practices for both sheep and cattle in sensitive areas have also been altered.

The water company is continuing to work closely with the regional health and local authorities, the Drinking Water Inspectorate and others within the water industry to minimise risks posed by the bug.

Those suffering from Aids and other immune deficiency disorders are advised to boil their water which, experts say, is the most effective way to kill the organism.

“Some of the work required includes major construction projects which will take two to three years to complete,” said Dr. West. “However, we are determined to complete this program as quickly as possible.”