Why is the Bathing Water quality so poor, and what should be done about it?
We held a well attended event in Newnham, Cambridge on 23 October 2024 to share the results of our investigations into the poor water quality in the River Cam, at the end of the first Bathing Season after achieving Bathing Water Designation.
Following the Environment Agency’s monitoring , it is clear that the official Bathing Water classification will be “poor”. This will trigger advice against swimming, investigations into the causes, and measures to fix them.
We’d expected a poor classification, but the results are shocking: every single E. coli test result is above the 90 percentile threshold of 900 colonies/100ml. The River Cam may well have the worst quality Bathing Water in the UK
Environment Agency Monitoring results for the River Cam, 2024 Bathing Water Season.
We want correspondingly urgent action to improve it, to protect the health of the many people that swim, kayak, paddleboard, punt and row on the Cam.
Our analysis of detailed monitoring done for us by Anglian Water during 2022-3 shows that Haslingfield Sewage works, 4km upstream is a big part of the problem. In summer, E. coli levels peak at the Sewage works, then steadily decline as the river flows past Grantchester Meadows to Sheep’s Green. In winter, and after rain, levels of E.coli are much higher, and they remain high as the water flows downstream
E.coli levels peak at Haslingfield Sewage Works, then steadily improve downstream towards Sheep’s Green
But our investigations show that other causes may also be contributing: its not JUST the sewage works.
These include frequent overflows from the sewage pumping stations in Harston, Haslingfield and Grantchester. These releases flow into various ditches, and then into the Cam
Dilute sewage in the street at Button End, Harston
The Rising Main (the pressurised pipeline taking raw sewage from the surrounding villages to Haslingfield Sewage Works) burst 3 times in 2022 and once in 2024
Raw sewage flowing from a burst Rising Main between Haslingfield and the Sewage Works in 2020
These various overflows have released sewage 35 times since January 2021.
This is in addition to the all too frequent overflows from the sewage works itself, which last year was revealed by Anglian Water’s EDM report to have been overflowing 30% of the time.
Surface water from Newnham Croft flows into the ditch at Paradise Nature Reserve. We think this may be also be contributing when it rains…
Newnham Croft surface water outfall into the ditch at Paradise Nature Reserve
After rain, the ditch goes brown. We’ve tested this for E. coli and as our presentation shows, after rain, E.coli levels reach 100,000 colonies/100ml . This shockingly high level is as bad as in the effluent being discharged from Haslingfield Sewage works.
We don’t yet know where this is coming from. Misconnections in Newnham could easily be a cause, because these are quite common, particularly from extensions when builders take “shortcuts”. These misconnections could be releasing sewage, or other “foul” water into Paradise Nature Reserve and the River Cam.
Dog mess might also be contributing.
A likely misconnection in Newnham Croft, with foul water pipes going into a rain water gulley
To help
Check that builders haven’t misconnected your drains (contact us if you want help)
Call the Environment Agency, immediately on 0800 80 7060 if you see suspected pollution incidents (this “evidence” helps the Environment Agency’s enforcement)
Never, ever, put wet wipes down the toilet (these cause blockages)
And join us on the ‘March for Clean Water’ on 3 Nov (show your support for tighter regulation, better enforcement and an end to pollution for profit)
We’ve organised a coach from Cambridge to the ‘March for Clean Water’, or you can make your own way by train. Do join us
Designation is a powerful tool to accelerate the cleanup of the river. Firstly, because it shines an official spotlight on the water quality. Secondly, because the water quality here will almost certainly be rated as “poor” it imposes Statutory Obligations on industry to reduce the pollution from sewage works, urban sewage overflows and agricultural slurry. Unlike general non-statutory calls to reduce pollution, the water industry responds to these Statutory Obligations, so this prioritises and drives real change. Some of the key pieces of legislation are the ‘Bathing Water Regulations 2013’ , WINEP, which governs the water industry funding and WISER (Water Industry Strategic Environmental Requirements) As explained here, following designation, Ofwat are likely to require the work to be completed by 2027. Without the statutory “Driver” of Bathing Water Designation, Anglian Water could take as long as they liked, so the improvements would be likely to take much longer…. maybe decades.
Designation helps accelerate the cleanup, but we’ll need to keep up the pressure for wider change too. Ultimately, we need to change our relationship with the natural world, so water can be good quality everywhere. However, this will probably take decades and the whole farming and water management system will need to change.
I’ve heard that areas with Designated Bathing Water status MUST promote bathing in the area, which will increase the number of visitor. Is this true
“3.—(1) Part 1 of Schedule 2 lists the surface waters that have been identified in England, other than excluded pools and waters, at which the Secretary of State expects a large number of people to bathe, having regard in particular to past trends and any infrastructure or facilities provided, or other measures taken, to promote bathing at those waters.”
We are informed that this means that it is a site that existing bathers use, with no signage prohibiting swimming, and where there are pre-existing facilities or infrastructure, such as steps, that support bathing.
We’ve also had confirmation from Clean River Ilkley that designation is not about marketing, and does not increase the number of visitors
Will designation increase the numbers of people coming to Sheep’s Green and the nearby Paradise Local Nature Reserve?
In the short term, no. We are counting “bathers” this summer, and we qualify for designation. (Defra require an average of over 100/ day on the 2 busiest days, and we counted 237 on 10 August and 184 on 19 August and 478 on 10 September)
We know the water quality on the Cam is very likely to be rated as “poor” which will require the council to put up a sign saying “Bathing is not advised”. This will deter rather than encourage swimmers. The experience of other river groups, such as at Ilkley in Yorkshire, is that designation has made no difference to numbers.
However, 3-5 years time, hopefully the water quality downstream from Haslingfield Sewage Works will have improved (something we’ve all been campaigning for). More people are then likely to feel safe enough to swim in the Cam at Byron’s Pool, Grantchester Meadows and Sheep’s Green.
We welcome more people connecting with nature, particularly in our highly unequal city.
When considering the Sheep’s Green area, it’s important to remember that the vast majority of the people that come to the area, do so to access the Lammas Land paddling pool, playground, cafe and local walks. When we counted visitors to Lammas Land and Sheeps Green on 19 August 3:40pm-3:55pm, only 2% were swimming in the river. This means that even if the number of wild swimmers at Sheep’s Green does ultimately increase, it will make very little difference to the overall numbers in the area.
Why choose Sheep’s Green, when most people swim at Grantchester Meadows?
Defra only allow applications from inland sites if there are toilets within 500m, and if it’s a short stretch of less than 500m. This ruled out applying for Grantchester Meadows. Nevertheless, designation will benefit the whole river between Haslingfield and Cambridge, and people will remain free to swim anywhere.
I’ve heard the council wants it to become a “Destination”. Won’t this increase numbers?
This rumour is based on a misunderstanding. It may have come from the section of the city council motion on 20 July that ‘affirms the goal …of having the water management plan for our chalk streams based on being an ‘environmental destination’ with subsequent protection as sites of Special Scientific Interest (SSSI)”.
Note that in water resource management government jargon, an “environmental destination” means a “long term goal”, not a “destination” in the tourism sense of the word. The council motion is about getting a higher level of protection for the chalk streams from abstraction, which is something we very much welcome.
I’ve heard people calling it a Designated Bathing Area or DBA, saying that this means it’s obvious its intended to attract people to a small designated area. Is this correct?
No. The correct name, used by Government is “Designated Bathing Water.” This is because bathing is NOT restricted to a small area. In a river, water flows though the site, so a large stretch of river benefits from clean-up as a result of designation .
Are you independent?
Cam Valley Forum is a voluntary group, established in 2001, registered with HMRC as charitable. We are entirely independent, and politically neutral.
As our website states, “We work with our extensive network of partners to protect and improve the environment of the River Cam and its tributaries” We frequently criticise the water companies and others for pollution and over-abstraction.
In 2021, when our volunteers started monitoring the Cam for faecal bacteria (ie bacteria from poo), we received a small grant of £1,500 from Anglian Water as a contribution towards the costs of laboratory analysis. In September 2022, Anglian Water took over the test program, and they are providing us with test results until September 2023. We are publishing these on our website here.
We think the public deserve to have more reliable, independent information on water quality, than that provided by volunteer citizen scientists like us, or by the Water Company itself. This is why we welcome the help of a very experienced and professional body like the Environment Agency, who have responsibility for monitoring Designated Bathing Water sites.
Will it be 100% safe?
Bathing Water Designation will reduce the chance of diarrhoea and vomiting from ingesting faecal bacteria.
Most people who swim in the Cam do so without problems, however wild swimming is never 100% safe, so you should make your own judgement (and keep your mouth shut while swimming). For certainty about safety, we advise swimming in swimming pools like Kelsey Kerridge, Abbey and Jesus Green Lido where the water is filtered and chlorinated, and the pool is supervised by lifeguards.
If the site becomes a Designated Bathing Water site, the City Council will have to display the Environment Agency’s annual water quality rating, in order to help inform the public of the level of risk. In addition to this, we are also encouraging the Council to display some Wild Swimming safety advice, as Oxford City Council has done at their Designated Bathing Site.
Anne Miller, Cam Valley forum’s lead on this says “I’m so pleased, and grateful for the hard work of everyonewho has helped, since Jean Perraton and Michael Goodhart started working towards bathing water designation back in 2020”
We are very hopeful that Defra will approve our application, and that this will unlock at least £5 Million in much needed investment from Anglian Water to help clean up the Cam. We know from the monitoring work over the last few years, that the aging and overloaded sewage infrastructure in the Haslingfield area is a major source of the faecal pollution of the Cam. This is resulting in such poor water quality that swimmers at times get sick, and it contributes to the phosphate pollution that is so damaging to habitats and wildlife. ”
“The investigation and improvements won’t happen overnight, but we hope that within a few years, it will be much safer for people to swim in the Cam”
Michael Goodhart said “The Town Bathing Place at Sheep’s Green has a history going back several hundred years, as a place where people could swim. Back in the 1960s my family would picnic and catch tiddlers along Rush and float rafts in the paddling pool. I was taught to swim in Snob’s Stream, before being allowing to dive into the main river Cam. I still love swimming in the river Cam, as do so many people. Bathing Water Designation provides a major opportunity for improving the quality of the river water for swimmers, boaters and also, very importantly we hope, for wildlife. “
Sheep’s Green in the 1970s
About bathing water designation for the Cam at Sheep’s Green
Cam Valley Forum will be applying to Defra for Bathing Water Designation for the Cam at Sheep’s Green, to improve the health of swimmers and help clean up the River Cam.
Summer evening at Sheep’s Green
Importantly, because the water quality is very likely to be offically rated as “poor”, designation should get us the investment we need to help clean up the river.
We are pleased to see that Anglian Water’s business plan, published on Monday 2 October, confirms this. In it, on pages 174-6, they say that IF the Cam gets priority, by becoming “Designated Bathing Water” they are budgeting ~£5M to improve Haslingfield’s ageing and overloaded sewage infrastructure. We need this!
However to apply for Designation, we had to have a formal letter of support from the City Council.
Our consultation has shown that designation is overwhelmingly supported by the community. We received 509 responses to our 10 week online consultation, the vast majority from the local area. 93% were in support. In addition to the City Council, we also have support from 18 organisations, ranging from Scudamores and Cambridge Canoe Club, to the Cambridge Federation of Women’s Institutes and South Cambs District Council.
The most common reason for supporting designation was wanting cleaner water in the Cam to reduce the health risks to swimmers and other water users.
The most common reason given for opposing designation, related to fears of significantly increased visitor numbers and that this would then damage precious habitats.
We share the concern to protect natural habitats, and much of our work is about preserving these. However, the fears of significantly increased numbers of visitors were in part due to rumours that the council would promote it as a visitor destination. These rumours are incorrect. Designation is simply about the health of bathers. There is absolutely no obligation to promote it as a visitor destination, so we are pleased that Councillor Sam Carling confirmed this several times during the meeting, and confirmed that the council has no intention of promoting it either.
Defra currently require us to submit 2 user surveys showing an average of at least 100 “bathers” on the 2 busiest days. Sheep’s Green has long been a popular bathing spot for communities across Cambridge, so our 2 surveys averaged more than 3 times this. However, as few people stay in the water long, we seldom saw more than 12 people in the water at a time.
We think this will have minimal impact on habitats, parks and nature reserves
A fox and paddleboarders watching each other at Sheep’s Green
A hot, but very pleasant day on Saturday 9 September, counting a total of 478 bathers in 4 hours at Sheeps Green. This is our record for the 2023 bathing season.
We already had two user surveys showing 184 and 278 bathers, which is well over Defra’s requirement of a minumum of an average of 100 bathers in 4 hours, in order to apply for Bathing Water Designation. However, as Saturday was forecast to be the hottest day of the summer, we decided to do another count.
As the afternoon temperature peaked at 32C, it was a joy to be in, on or near the river. We counted 478 bathers (ie swimmers, or children paddling) in just 4 hours.
Kids and adults swim from the quayside
Making a big splash
Teenagers congregate at Hodsons Folly
Small children and their parents enjoy paddling in the Rush
Worryingly, some people believe that the Rush is a fresh water spring (despite the clear notice saying that its river water). We were told someone had even been drinking from it. This is not a good idea (particularly as there’s a drinking fountain near the cafe)
Very pleasant on the grass by the quayside…
and the Sheep’s Green picnic area was peaceful….
while the Lammas Land paddling pool was heaving…
the Cafe was busy..
and as usual, a few people had parked in stupid places.
Ably and fairly chaired by Jeremy Sallis (formerly of BBC Radio Cambridge), the room was packed with 62 attendees. A wide range of views were heard: Friends of the Cam handed out leaflets and spoke powerfully about their opposition to the principle of designation and their outrage at Anglian Water. Others spoke equally powerfully about the benefits of designation, particularly for the health of swimmers, Cambridge’s young people and their access to nature.
The main concerns related to increased visitor numbers. DBW would be a minor factor in increasing visitor numbers but there are a lot of other factors related to warming climate and less long distance travel for leisure that are likely to be stronger, given that the designation will result in advisories against swimming until improvements in quality can be achieved. Many people in the audience felt that visitor numbers to all green spaces in Cambridge are increasing and likely to increase for multiple reasons and this is good, and obviously will in the long-term need managing – but this should not be stopping us cleaning up the river.
The overall feeling of the meeting was supportive of designation.
One participant emailed us with her reaction to the event as follows
“Many local residents came along and put paid to the oft repeated fallacy that local people don’t want designated bathing water at Sheeps Green. The overall feeling was supportive……. every attendee received FotC leaflet, and I felt counterarguments most certainly were heard and given space to be expressed. Overall the takeaway was ‘don’t let perfect be the enemy of good’ – all these local pressure groups can and should campaign on many issues for better river health, changes to environment legislation and designation process, but just because DBWs don’t fix all problems all at once does not mean it’s not worthwhile.“
Michael Goodhart, sharing some of the 400+ year history of swimming in the Cam
Anne Miller, explaining why Cam Valley Forum proposes applying for designation
Simon Spooner explaining how the water industry works
Olwen Williams sharing her concerns for Paradise Local Nature Reserve
Success! Having counted 184 bathers on Saturday 19 August, and 237 on Thursday 10th August, we now have the evidence we need to show Defra that there are sufficient bathers to qualify for Bathing Water Designation
Although it was a breezy day, so not as inviting for swimming as our previous count on Thursday 10th August, we still achieved well over Defra’s threshold of a minimum of an average of 100 bathers/ day, counted over 4 hours on the 2 busiest days of summer. Few people stay in long, so the river never felt busy.
It was a lovely afternoon, watching people enjoying themselves, and chatting with the swimmers.
This is an important place for people to come to for exercise
Artistic Swimming at Sheep’s Green
As it was a weekend, there were more punts, canoes and paddleboarders out on the river, than during the week, but everyone mixes along. Unfortunately Defra only allow us to count people as “bathers” if they actually go in the water at Sheep’s Green… But some did!
Wild swimming is a minority activity so, as usual, Lammas Land a few hundred meters away, was way busier. In late afternoon, we counted 149 adults and 110 kids there, with another 7 adults and 13 kids at the learner pool, ie 279 in total.
With just 5 people in the river at the time, this suggests that wild swimmers are only around 2% of the visitors to the area.
On Thursday 10th August, the Cam Valley Forum team had a glorious afternoon at Sheep’s Green, and counted 237 bathers over the busiest four hours.
This is way higher than Defra’s requirement* to show a minimum of 100 “bathers” per day over the 2 busiest days of the summer. Nevertheless, the river never felt at all crowded.
Typically, at any one time, there were 2-10 swimmers in the river, and a similar number of small children paddling in The Rush. It was a warm day at ~26C, but after weeks of cold weather, the water was still cool at ~14C, so few stayed in longer than a few minutes. The river never felt busy.
(For those interested in the maths… if a site had an average of 5 bathers in the water at any one time, each staying in 5 minutes, that would result in 60 bathers / hour, or 240 bathers over 4 hours)
Swimming in the river gives so much pleasure: Small children and their parents picnic and play by The Rush. Adults and older kids swim from the Canoe Club quayside, while the teenagers gather at Hodson’s Folly, socialising and swimming.
Here are a few of the voices from the afternoon.
Ann learnt to swim here during the War, and still swims here
“Do user surveys on 2 days during the bathing season to count the number of people bathing.… Do your user surveys for up to 4 hours at the busiest times of day. The 4 hours can be consecutive but do not need to be. For example, you can survey the site for an hour at a time at different times throughout the day, or survey the site for 4 hours in one go. Defra will use your surveys to calculate the average daily number of bathers“
We did our user survey in accordance with this, counting in four, 1 hour sessions between 12:30 and 16:50 on 10 August 2023.
We hope to do another count, later in the bathing season. Let us know if you’d like to help.
Our Consultation: if you haven’t yet done so, please respond to our consultation here and/or come to our Consultation Event 6pm Tuesday 29 August, in Newnham Sports and Social Club.
We are very pleased that at the full Council Meeting on 20 July 2023, Cambridge City Council voted overwhelmingly to approve Cllr Katie Thornburrow’s motion (with a supportive Lib Dem amendment) in support of our proposed application for bathing water designation, subject to consideration by the Environment & Community Scrutiny Committee on 5 October.
The key section of the approved, ammended motion included the statement that : “This Council.. Agrees to evaluate the potential of a formal application to Defra for an inland water stretch along the River Cam within Cambridge City Council boundaries to be designated as a bathing site, working with Anglian Water and local partners such as Cam Valley Forum, in order to secure an improvement in water quality while also taking into account the impact of any increased usage and avoidance of significant additional cost; and requests a report on this to the Environment & Community Scrutiny Committee to inform a balanced decision by the Executive Councillor.”
We welcome this addition to our consultation process.
Bathers at The Rush, Sheep’s Green cambridge
Why do we want to apply for bathing water designation?
Cam Valley Forum wants to apply for designated bathing water status for Sheep’s Green, because this is the most powerful way we have to improve the water quality in the Cam, for the benefit of swimmers, paddling kids, punters, kayakers, our rowing crews, other river users. We hope that a reduction in sewage pollution will also benefit our wonderful natural habitats.
The requirements for designation were changed a few weeks ago, and there is some confusion about this, because the DEFRA website is confusing. However we’ve had clarification from DEFRA that they want to see evidence that an average of at least 100 “bathers” a day use the proposed stretch, at least briefly during the peak 4 hours, averaged over just the 2 peak days of the summer bathing season. We are currently gathering this evidence, so you may see CVF volunteers out counting bathers at peak times at Sheep’s Green. Our impression is that, assuming we have some nice weather this summer, the current bather numbers at our proposed stretch (from Hodsons Folly to The Rush) are sufficient to achieve designation.
It is important to note that designation is about protecting the health of existing “bathers” not attracting new ones. The experience of other inland river groups, such as at the river Warfe at Ilkely in Yorkshire is that designation results in no change in visitor numbers, not least because it highlights the “poor” water quality (as we currently have in the Cam)
This “poor” classification then creates statutory obligations under the Bathing Water Regulations 2013 that should accelerate the much needed improvements in Haslingfield sewage works.
This is why councils and community groups across the country are applying. Sixteen inland sites have already achieved designation, including Wolvercote Mill Stream in Oxford, the River Wharfe at Ilkely, and the River Deben at Waldringfield in Suffolk. Hundreds of coastal sites have of course, had designated bathing water status for years.
Cam Valley Forum urges Cambridge City Council to pledge to support a Bathing Water Designation Application for the River Cam at Sheep’s Green, because of the environmental benefits that it will bring.
This (shown in yellow) is the popular swimming stretch on council owned land, near the Lammas Land carpark, café, toilets and playground, Canoe Club, Learner Pool and Paddling pool. Subject to further consultations, we envisage applying for designation of the stretch from Hodsons Folly (just upstream of the footbridge) downstream to the popular childrens paddling area of The Rush. Our aim is to submit this in October 2023
A successful application would genuinely help clean up the Cam.
Cam Valley Forum has been campaigning for a Bathing Water Designation for the Cam at Sheeps Green since 2021. During the pandemic we carried out an initial consultation to understand the issues and counted bathers. Since then we have been monitoring the water quality, both as a citizen science project, and with Anglian Water. In September 2022 we were very pleased to see that Cllr Pippa Heylings’ motion about investigating a Bathing Water Designation was passed by South Cambs District Council.
A successful Bathing Water Designation application would have real benefits for both the environment and for residents.
As Surfers Against Sewage point out, “Bathing Water Designation shines a light on the water quality at a specific site which puts polluters in the spotlight. Once designation is granted there is a legal obligation for polluters to clean up their act and also a requirement that the government agency for your region tests the water quality throughout the bathing season. Your bathing water will be tested for Intestinal enterococci and Escherichia coli, otherwise known as E.Coli. At the end of the bathing season the designated site will be given a classification of: Excellent, Good, Sufficient or Poor”
Importantly, the rating of “Poor” should also release the OfWat funding that will help fix the sources of pollution (we think Haslingfield Sewage Works is a major part of the problem).
We also think the City Council also has a moral duty to support an application.
In summer hundreds of city residents a day enjoy swimming in the Cam, paddling in the Rush or jumping into the river at the Sheeps Green footbridge, while hundreds more enjoy the river on punts, kayaks, canoes and paddleboards, some of whom also fall or dive into the water at times. We know wild swimming brings huge benefits in reducing stress, improving fitness and wellbeing and contact with nature. Importantly, its also free. This is a vital source of recreation in our highly unequal city, with many city residents terrified about how they’ll survive the cost of living crisis.
Swimming at Hodsons Folly
A summer evening outside the Canoe Club
The Children’s Paddling Area at “The Rush”
Nevertheless we know the pollution level is frequently unsafe, and at times people become seriously ill. Swimmers at Newnham Riverbank Club further upstream and our rowing teams downstream are also affected. We think the City Council has a moral duty to support an application, both to inform swimmers about the state of the water, and because it will unlock the funding that will help provide a solution.
Although, during the pandemic, some were concerned that designation would result in swarms of visitors, we think this is most unlikely. Our likely rating of “poor” would be more likely to deter rather than encourage visitors. Many other inland sites now have bathing water designation, including Oxford, the River Deben in Suffolk, the Serpentine in London and several Country Parks. Cambridge would just be one of many designated sites.
Surely we can’t let Oxford outdo us in taking serious action to clean up our river?
