Water & Wastewater Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/741165
www.wwtonline.co.uk | WWT | OCTOBER 2016 | 27 Barry Hopton MuniCipal BusinEss ManagER aTg uV TEChnOlOgy the old enemy all was quiet on the Cryptosporidium front but now the water industry's bête noire has re-surfaced. What can water companies do to address its threat? In the know Getting to grips with... Cryptosporidium a specially commissioned emergency turn-key uV container to protect against Cryptosporidium was manufactured, assembled and tested in less than 2 weeks at atg uV's facililty in lancashire C ryptosporidium incidents are thankfully fairly rare, but when they do occur they bring high-profile misery to the water supply industry. The Drinking Water Inspectorate (DWI) is currently investigating an incident which occurred last year, and, if it concludes that system changes are necessary to ensure that similar incidents will not occur in the future, this could result in a delay to the opening of the business water retail market. If a further water quality incidents were to occur during the shadow market period, which started in October 2016, the DWI could lose confidence in the ability of the industry as a whole to manage an incident, resulting in a complete rethinking of the future arrangements as they currently stand. So what can the industry do about Cryptosporidium? What is Cryptosporidium? Cryptosporidium is a parasitic protozoan that infects a range of animals. In humans, it remains in the lower intestine for up to five weeks causing cryptosporidiosis, an illness characterised by diarrhoea, o…en accompanied by stomach pain, nausea or vomiting, fever and sometimes dehydration and weight loss. Healthy people usually recover quickly but those with a compromised immune system or with other medical conditions may be more seriously affected and cryptosporidiosis can be fatal for those receiving chemotherapy or for AIDS patients. So it's a real health risk. How does it spread? Infected animals excrete the organism in the form of oocysts – a sort of egg with a tough outer shell that protects it from the environment – that can survive for long periods and which find their way into water sources. Streams running through grazing land are an obvious problem, but poorly protected wells and boreholes can also be at risk. Other animals then ingest the oocysts when they drink the water and the cycle starts again. Two species cause human cryptosporidiosis. C.parvum generally occurs in farmed animals and C.hominis appears to be specific to humans. How does it get into supply? Provided that the Badenoch/Bouchier recommendations are followed, a conventional water treatment plant should remove the oocysts, but failures can and do occur, resulting in contamination of the supply. There is also potential for post-treatment contamination - for example, oocysts entering the distribution system from pipe fractures. Cryptosporidium is very common so these risks are ever- present. How easily can it be detected? Probably the biggest problem of Cryptospordium is the difficulty of detection. Oocysts are particulate and about 5µm so they can be detected