Water watchdog rethinks evidence after case fails

Water companies suspected of supplying unsafe water may escape prosecution after a High Court judge cleared South West Water of supplying water unfit for human consumption, even though 575 of its customers suffered ill-effects from cryptosporidiosis.

The Drinking Water Inspectorate relied for its prosecution on an epidemiological report by a local health authority's outbreak control team. But the report was ruled inadmissible by the judge, who recorded a not guilty verdict against South West Water.

Mike Waite, a principal inspector at the water watchdog, said the ruling meant that it would have to reconsider prosecutions already in the pipeline and consider suggesting legislative changes to make future prosecutions involving epidemiology easier.

He said: “It is easy to prosecute for aesthetical matters, you just need a few statements from people who saw it. The difficulty comes when it comes down to health. Epidemiology has never been a basis of a case before.”

In the only two previous prosecutions for supplying water unfit for human consumption (under section 70 of the Water Industry Act) Severn Trent Water and Thames Water were both convicted for supplying water with “unacceptable taste” and discoloured water, respectively.

The inspectorate had been considering prosecuting Three Valleys Water for an outbreak of cryptosporidiosis in north London in March this year in which 32 customers fell ill and the company advised 300,000 households to boil their drinking water. But a prosecution no longer looks likely in light of the South West Water case.

The epidemiological report by local health officials concluded that the outbreak in south Devon over two months in autumn 1995 came from an area supplied by one of South West Water's water treatment works.

But at Bristol Crown Court last month, Judge Bursell QC ruled that the report was inadmissible because it relied on 500 questionnaires which, for reasons of medical confidentiality, were anonymous.

Because they were anonymous, South West Water could not check them for its defence, the judge said.

The report also stated that laboratories found cryptosporidia in the faecal samples of 575 individuals. However, the judge required statements from the laboratories and the individual victims that each sample belonged to the correct individual.

“In the worst case,” said Waite, “we would have had to supply six statements for every infected individual – that's 3,000 statements. I do not think there has ever been that many statements in any legal case.”

He added: “The problem is that outbreak control teams are not set up with a remit to collect evidence for a criminal prosecution.”

The inspectorate asked for an adjournment of six months to give it time to collect all the necessary statements, but the judge ruled that this should have been done beforehand.

“We have got a problem here,” admitted Waite. “I am going through the judge's legal arguments at the moment and will produce a report. We need to find out if there is anything we can do in the way of collecting more evidence in future cases and also if the regulations can be revised to make these sort of prosecutions easier. There is no definition of 'unfit water' at the moment.”

South West Water was advised by Herbert Smith partner Tony Dempster and assistants Michael Wishart Allan and William Glassey. The Drinking Water Inspectorate used Treasury solicitor Jacqueline Duff.