A swimmer believes he contracted a disease from swimming in the Thames amid fresh concerns about sewage in the river.

Nigel Downes, who is a regular swimmer of the river, usually plunges into the stretch between Bourne End and Cookham which is downstream from the Little Marlow Sewage Treatment works.

He believes he has picked up the disease giardia from alleged contamination of sewage into the river, and says that ‘some real-time alerts’ should be issued when ‘raw sewage is being released into the Thames’.

Giardia is a diarrhoeal disease that can cause diarrhoea and stomach cramps.

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Speaking to the Free Press, Mr Downes, who lives in Cookham, said: “A number of Marlow schools row in this section of the river and there has been a huge increase in the number of open water swimmers and paddleboarders since lockdown.

Sewage issues have been a regular occurrence in South Bucks

“I guess ultimately I’d like to ensure that the leaks stop happening but realistically, it would be good to campaign for some real time alerts when raw sewage is being released into the Thames, raise people’s awareness that it happens and the consequences to the environment and the potential hazards to recreational river users health.

“I think that the timing is particularly crucial now as the temperature warms and many people will be having staycations.

"I know that Thames Water complain about the Victorian sewers they have inherited, which mean they are overwhelmed when they have stormwater mixing with sewage running through them, but it would be really interesting to know what solutions they are considering and the cost of these.

“I believe that they are permitted to release some sewage into the river when there are storms but I’d be interested to know how much and when.”

Bucks Free Press: Steve Backshall and his wife Helen Glover live in Marlow (PA)Steve Backshall and his wife Helen Glover live in Marlow (PA)

READ MORE: Steve Backshall hits out at Thames Water over sewage leak

In March and April of this year, Thames Water were heavily criticised by residents in the area, which included TV presenter Steve Backshall, for pleading guilty to the death of thousands of fish at Fawley Court Ditch in Henley, Oxfordshire.

They were fined £2.3m for the incident which happened in April 2016.

The company was also fined in 2017 after they pumped nearly 1.5b tonnes of sewage into the river, which resulted in the deaths of hundreds of fish and birds.

However, Thames Water have since revealed that following the spills in the spring, there have no further incidents and that they are trying to make several key changes to how they operate.

Bucks Free Press: Sewage leakages have been an issue in South BucksSewage leakages have been an issue in South Bucks

In a Q&A that we sent Thames Water, they said the following:

Following the issues at the start of the year, how and why has sewage made its way back into the Thames?

"Following the incident in March, there were no further spills from Little Marlow sewage works during April or May. Water quality testing was carried out at the time which showed no adverse effect on the river.

"There are many other sources of bacteria and parasites in rivers, such as from livestock and other animals, along with pollution from farming, industry and roads."

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Should people be worried for going for a swim this summer in Thames? As many rowers go up and down that stretch of the Thames, and along with Mr Downes’ recent diagnosis, is this stretch of the Thames currently safe for people to use?

"It’s not for Thames Water to say whether it's safe for people to swim in open water.

"It really is up to individuals to make informed decisions based on several factors.

"As mentioned above, there are many other sources of bacteria and parasites in river water, such as from livestock and other animals, along with pollution from farming, industry and roads.

"We support the Government’s advice on open water swimming."

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What can be done to improve on this in the future?

"We want to do the right thing for our rivers and the communities who love them.

"We're committed to protecting and enhancing them.

"Putting untreated wastewater into rivers is unacceptable to us, to our customers and to the environment.

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"But after heavy rain it is sometimes necessary, and permitted, as a last resort, to prevent it from flooding homes, gardens, streets, and open spaces.

"We're working hard to make discharges unnecessary, with the help of the government, Ofwat, and the Environment Agency.

"We recognise that real-time discharge notifications play an important part in helping people make informed decisions about whether to use the river or not.

"We're trialling these notifications around Oxford to support an application for bathing water status.

"Details on this can be found here.

"We're looking to adopt a similar approach for our other wastewater catchments in the future.

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"We’re upgrading Oxford and Witney sewage works to improve capacity and we’ve launched our Smarter Water Catchments initiative which sets out how we’ll collectively protect and enhance the rivers Chess, Evenlode and Crane over the next 10 years.

"These plans were created in partnership with 67 organisations who have an interest in these rivers and seek to find innovative solutions to improve water quality, reduce surface and groundwater flooding and increase biodiversity. We will be looking to expand this approach to other catchments from 2025 onwards."

Will this be rectified sooner rather than later?

"We’ve developed a turnaround plan which focuses on significantly improving our performance, with an unprecedented amount of investment directed towards safeguarding the environment.

"We’re committed to long term sustainable solutions and we’re already working with partners across our region to enhance and restore the rivers we all share and value.

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"Our business plan for the next five years will deliver environmental improvements to 745km of rivers across the region.

"The use of digital technology to create a more intelligent network and enable more proactive maintenance and repair will help drive a step change in pollution reductions.

"Eliminating discharges is not going to be quick, easy, or inexpensive and we welcome the continued support of our customers and regulators, who are equally passionate about this topic, as well as extensive collaboration with local communities and other stakeholders, to achieve cleaner rivers.

READ MORE: 'Shame on you' - Thames Water slammed over sewage in River Chess

"We absolutely want to go further, invest more, and play our part in helping the environment to thrive.

"There is a long way to go – and we certainly can’t do it on our own – but the ambition is clear."