Inspectorate concludes Pitsford incident investigation
Posted: Wednesday 17th December 2008
The Drinking Water Inspectorate has published its independent assessment of the incident involved the issuing of a boil water notice to some 258,000 consumers living in the Northampton and Daventry area in June 2008.
The Inspectorate has concluded that the cause of the incident was a failure of basic water supply hygiene arrangements at Pitsford works operated by Anglian Water. This oversight by the company allowed a small rabbit to gain access to a wash water tank. The consequences of this were that the entire drinking water distribution system became contaminated by a strain of the Cryptosporidium parasite which infects rabbits. Prompt action by the company ensured an appropriate and effective multi agency health protection response. Although a large number of consumers were inconvenienced by the need to boil their drinking water, this precautionary advice undoubtedly played a vital role in keeping the adverse consequences for human health to a minimum.
In concluding the investigation, Deputy Chief Inspector Marcus Rink said :-
“ my inspector is critical of this failure of basic water supply hygiene arrangements however his assessment rightly highlights how it was Anglian Water’s own robust monitoring procedures which raised the alarm and secured a quick and effective multi agency response”
The enhanced health surveillance put in place following the alert subsequently found that 22 people contracted Cryptosporidiosis due to the same genotype of the Cryptosporidium parasite found in the rabbit and water samples, prior to this incident only a single case of human infection with this strain had been recorded anywhere in the world.
The Inspectorate has acted to close gaps in scientific knowledge revealed by this incident . It has commissioned studies into the rabbit genotype of Cryptosporidium led by the UK Cryptosporidium Reference Unit , NPHS , and funded by DEFRA.
Commenting on this work Professor Jeni Colbourne MBE, Chief Inspector of Drinking Water, said “ Consumers can be assured that action has been taken to learn from this incident “.
In a stark message to the water industry she said “ my inspectors consistently reinforce the need for close attention to be paid at all times to water supply hygiene arrangements; this incident shows how anything less than constant vigilance is unacceptable”.
