On Friday, with just over a week to go until the Wild Dart 5k, and my longest training swim of 4.6km behind me, I headed to the Oxford WaterBlitz event which The Rivers Trust has helped organise, and I was hoping to squeeze in a swim in the Thames whilst I was there.

Through our Together For Rivers campaign, we’ve been supporting local bathing water campaign groups to monitor water quality in popular swimming and watersports locations. The End Sewage Pollution Mid-Thames campaign kicked off last summer in response to the publication of our map of untreated sewage discharges which showed just how often this is happening – over 50,000 times in the upper Thames in 2020! After a floating protest on the river, the group gathered over 5,000 signatures on a petition, which led to Oxford City Council unanimously supporting an application for designated bathing water status.

If the application is successful when submitted later this year, this will be only the second river in the UK to achieve this recognition. Designated Bathing Water Status would require the Environment Agency to monitor water quality throughout the summer, and would provide a mandate for Thames Water and other polluters to tackle the upstream sources of pollution. The Rivers Trust and Thames21 have been working in partnership to gather data on the level of recreational use and the water quality in Oxford and upstream to help support the application.

For the last few months, trained volunteers have been gathering samples to take to a nearby laboratory so that the water quality can be assessed against the EU Bathing Water standard. 18 sites are being monitored on a rota, but last week we ran a ‘WaterBlitz’ day and took samples at all the sites on the same day, including several samples throughout the day in the city to see how conditions changed over time.

The weather on the day was less than ideal, with torrential rain forecast, but a dedicated group of volunteers braved the conditions to come and gather water quality samples at 18 sites across the catchment in one day. When we arrived at Portmeadow in Oxford, Claire Robertson (the campaign lead) was just drying off after an early morning dip in the river. I was tempted to jump straight in, but we had work to do training the volunteers in the sampling methods and ensuring that all the survey kit was distributed to the different groups.

Later when the opportunity arose for a swim, we were all pretty cold and wet as the gazebo had been no match for the driving rain, however I knew from experience that the water would feel relatively warm at this time of year. I really love swimming in the rain – there is something pretty magical about being in or on water when the rain is hammering down and you literally can’t get any wetter. However, there is a big downside to wet weather swimming, which is the worry about pollution washing off farmland and being discharged through combined sewer overflows (CSOs) or overflowing septic tanks in to rivers and the sea.

Despite the fact that we were taking samples all day, we wouldn’t have any data back for a couple of days as it takes this long to incubate bacterial samples in the lab. Finding a rapid and affordable test which provides a count of E. Coli and Intestinal Enterococci (Faecal Indicator Organisms) and therefore tells us whether our rivers are clean enough to swim in when we are at the bankside is the holy grail! There are kits which have been developed to give near real-time results, but these are expensive and therefore can’t be deployed everywhere people wish to swim. We were testing out a new bit of kit from Tecta, which gives a result within one day, but this still leaves the swimmer wondering whether it’s safe to swim now! Armed with the knowledge that the rain had only recently set in, that some recent samples had passed the bathing water standard, plus the Thames Water CSO spill notifications hadn’t yet gone off, and the water looked pretty clear and smelt ok, I decided to risk putting my face in for a bit of front crawl. Our early Tecta result for that site looks like it was a good call, but watch this space to see what the lab results show and how the new kit compares.

I won’t have the luxury of prior knowledge or expensive test kits or lab tests when I do my Dart swim, and there some rain forecast, so I’m keeping my fingers crossed that my 13 year old daughter and I don’t get sick due to pollution and runoff. I dearly hope that by the time she is my age, untreated sewage and farm pollution in our rivers are a distant memory, and she can enjoy the many health benefits and joy of immersion in a natural environment without worrying about getting sick as a side effect.