Hotels and restaurants in one of the country's most popular seaside holiday destinations could be seriously impacted following a contamination.
Hundreds of people across Devon have fallen ill with diarrhoea, vomiting and stomach pains amid the parasite outbreak in contaminated taps.
South West Water (SWW) has urged people to boil their tap water in order to prevent further sickness. Meanwhile, people are panic buying water from supermarkets, with photos shared on social media of empty shelves.
The Hill Head reservoir and the wider Alston area are being investigated by the company as a potential cause for the outbreak - an area which about 40,000 residents get their water supply from.
Residents in Devon picking up clean water
PA
Locals were seen queuing up for water
PA
Now, nearby business owners have reported that they are already seeing the impact of the contamination.
John Ingram of The Bay Coffee Company in Brixham told the Daily Mail: "We can't give anybody a glass of water. It is affecting trade - a lot more people are just not coming out. Everyone is now worried about getting ill."
Attendees at Brixham Pirate Festival, which took place between May 4 and May 6, have also reported sickness.
Local Meg Dew said: "My 62-year-old mum called me about half an hour ago, she has a bad stomach and diarrhoea...My friends have been ill since the Pirate Festival... I didn't even know until this morning that there was anything wrong with the water."
LATEST ON THE CONTAMINATED WATER SCANDAL
Workers at Hill Head reservoir in Devon
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Co-owner of the Venus Cafe near Brixham Michael Smith told the BBC they had seen a 40 per cent drop in business in the last two days and had not been contacted by SWW "in any fashion."
He said: “During the week at the minute we’re not super busy, but we’re losing £400-500 per day the last couple of days. Come the weekend, sunshine next week and the week after, we’re talking many thousands."
Asked if for lots of residents the parasite could still be in the incubation period, professor in medicine at the University of East Anglia (UEA) Paul Hunter told BBC Breakfast: “Absolutely.
“One of the problems when you’re investigating outbreaks like this is that the incubation period can be about 10 days to two weeks, so often in the past when I’ve been involved in investigating outbreaks by the time you know you’ve got a problem, the problem has resolved itself anyway, but you can’t guarantee that.
"Even if they have stopped all new infections by now, you would expect to see further cases for at least 10 days to two weeks."
WATCH: Locals in Brixham speak to Jeff Moody about the contaminated water
A South West Water spokesperson said: "Customers in Alston and the Hillhead area of Brixham are advised to boil their drinking water before consuming following new test results for cryptosporidium.
"We are issuing this notice following small traces of the organism identified overnight and this morning.
"We are working with the UK Health Security Agency and other public health partners to urgently investigate and eliminate the source.
"We apologise for the inconvenience caused and will continue to keep customers and businesses updated. Bottled water stations will be set up in the affected areas as soon as possible."