A lifeboat volunteer who fell ill from a microscopic parasite linked to human sewage has blasted the state of the Wye and Severn rivers.

Severn Area Rescue Association lifesaver David Deveney has revealed that he contracted giardiasis after spending two hours in the water during a training exercise at Beachley beside the old Severn Bridge, close to where the Wye enters the estuary.

The SARA lifeboat training manager spent more than a week in hospital in two admissions and was off work for nearly four weeks with the illness, which doctors told him was 80 per cent likely to have come from water contaminated with human sewage.

And following Welsh Water’s latest figures showing more than 1,600 reported spills into the Wye in 2021, he has warned river users to be aware of the potential danger.

Mr Deveney, from Caldicot, told the BBC he fell ill the evening after the exercise in October 2020 and was vomiting for three days along with severe diarrhoea.

His GP said he had probably swallowed the live bacteria in the water, as he hadn’t drunk untreated water or eaten in a restaurant.

After spending three days in hospital, he was sent home, but was readmitted after five days when his condition worsened again.

Mr Deveney, an HGV recovery technician who lost weeks of work, told the BBC: “I wouldn’t wish it on my worst enemy. I’ve been through physical hell with the after-effects of the contaminated water.”

And he added: “They said it was an 80 per cent chance of human slurry or human waste.

"It turns your stomach when you think about it… you’ve ingested that through no fault of your own when you thought you were just messing around in a normal river.

“It’s an ecological catastrophe on my doorstep…

"I think it would be very difficult to pinpoint it to one organisation, maybe one farm or one sewage outfall, but it made me think about my water intake.

"It won’t stop me volunteering as a lifeboat helmsman or as an instructor, but we now try and carry more antibacterial wipes or try not to have the head submerged in the water as often as we did before."

The NHS said the notifiable disease is caused by the giardia parasite and can be contracted by drinking untreated water.

Public Health Wales told the BBC it could not comment on specific cases.

Mr Deveney said he was told by investigators that heavy rains and high tides at the time meant the River Wye was the most likely source.

The BBC said the latest figures from Welsh Water indicate “more than 94,000 reported spills of sewage into Welsh rivers in 2021, with the discharges lasting for more than 785,000 hours”.

In the Wye and its tributaries, there were 1,678 reported spills for a total duration of 10,315 hours.

But Mr Deveney said crews had "no choice" but to go into contaminated water to help people in trouble.

"We know the contamination risk but somebody that needs our help, we will still go and help them," he told the BBC.

"We’re always on the lookout for… contaminated water.

"You see brown, you see toilet paper in some parts of it, condoms, sometimes sanitary products and when you think of it being in your river and the kind of brown foam you get in turbulent water."

With the weather warming up, paddle boarders, kayakers and swimmers are returning to the Wye, but he warned: “Sometimes it’s not the nicest environment.

"It’s not an advert… for the Wye Valley, and I would discourage people from swimming in it… and that goes against my belief in enjoying the water."

Welsh Water told the BBC sewer overflows played a "vital role" in preventing homes from being flooded, and that the system in Wales flushed by surface water is "highly monitored”.

"We are pleased that our investment in recent years has played a part in helping reduce the number of spills by 10 per cent in 2021, despite us adding monitors to an additional 198 combined sewer overflows in the same year," a spokesperson said.