Wallingford Beach is located on the eastern bank of the River Thames, immediately south of the Wallingford Bridge. This stretch of river is popular with swimmers and other river users year-round and is a site of cultural and natural significance to the town.
Here’s what citizen scientists have discovered about the site’s water quality.
Testing the Waters
The site was designated with bathing water status in 2024, following an unsuccessful attempt in 2023. Undertaken alongside both applications was a water quality monitoring programme, testing for bacteria at the proposed designation site. Citizen scientists have been integral both to the designation and to these wider water quality projects, joining forces to conduct user surveys and take weekly water samples.
The 2022 bathing season was characterised by dry and hot weather, and E. coli (EC) and Intestinal Enterococci (IE) levels remained low throughout, with an overall ‘Excellent’ status for EC and an overall ‘Good’ status for IE. Meanwhile, in 2023, overall bathing water status was brought down to ‘Poor’ and ‘Sufficient’ by higher EC and IE levels in late September correlating with heavier rainfall. In 2024, overall status was also brought down by sample dates that correlated with heavier rainfall in July, lowering the E coli status to ‘Poor’.
Thames Water has made improvements to both Benson and Dorchester sewage treatment works (STWs) in the last two years, which are both located upstream of Wallingford Beach. These improvements are expected to reduce untreated discharges after rainfall, which appears to have been successful at Dorchester STW which recorded no discharges during the 2024 bathing season. Benson STW, which did record discharges this summer, has been upgraded to increase capacity, but Thames Water are investigating groundwater impact[1] at the site. They expect to publish the results of this investigation and plans for improvements in the next Asset Management Plan (2025-2030). This season’s results make it clear that Wallingford Beach is still at risk of degradation of water quality after periods of rainfall, but that it is within reach of ‘Good’ water quality status, which would have been achieved if not for one poor sample result following heavier precipitation in July 2024.
Thames21 is working with local authorities and communities and will advocate for investigations to be expedited, as those at Ilkley and Wolvercote, the country’s first river bathing water sites, have proven to be slow, extensive processes that perhaps do not fit with Defra’s current timescale of de-designation, designed to fit conditions at coastal bathing water sites.
Figure 2 – Wallingford Beach bathing water site (Image credit: Thames21)
Figure 3 – Thames21, local authorities, campaigners, and swimmers pose with bathing water designation signage at Wallingford Beach (Image credit: South Oxfordshire District Council)
Hear from the citizen scientists
“As a local resident and avid wild swimmer, I am delighted to hear of the successful application for the River Thames bathing water status at Wallingford Beach. This river holds a special place in the hearts of many in our community, offering not just a source of recreation but a vital connection to nature.
Being able to swim in clean, safe waters is not just a luxury but a right for all who call this area home. This achievement not only enhances our quality of life but also underscores our commitment to environmental stewardship. It’s a testament to the collective effort of residents, authorities, and environmental organizations working together for a healthier, more vibrant Thames.
I volunteered to take part in the citizen science monitoring as part of this application because, being a freshwater ecologist, ensuring the water is clean enough for our wildlife to not only survive, but to thrive is very important to me.
I look forward to many more refreshing swims in these revitalized waters, knowing that we are safeguarding this precious resource for generations to come.”
Citizen Scientist and Swimmer, Wallingford 2024
