South West Water has lifted its boil water notice for a further 900 properties in Devon after traces of cryptosporidium were detected in the system last month. Originally around 40,000 properties were told to boil their water following the outbreak, caused by a damaged air valve casing on private land. David Harris, incident director at South West Water, said the company had “thoroughly cleaned” its network and had “added a double layer of protection using ultraviolet treatment and specialist microfilters to provide additional barriers”.