Making a Splash - New and innovative approaches to monitoring bathing waters

There are more than 600 designated bathing water bodies across the UK, and this includes coastal waters and inland sites. Bathing waters are assessed on an annual basis by regulators, using standards that focus on microbiological quality. These standards have been derived from public health guidance, and relate to the potential public health risk of gastrointestinal illness arising from swimming in natural waters.

The rising popularity of “wild swimming”, in combination with increased awareness of pollution from sewer overflows, means that there is an enormous amount of public attention on bathing waters.

Historically, information on bathing water quality has been provided on boards situated by the designated bathing water body, which are updated by the environmental regulators. However, this information is usually either generic, refers to the previous classification year, or is at least one week out of date.

Modern technologies mean that we can now start moving towards providing more detailed and near real-time information to bathing water users.

So which new innovative technologies may help us better protect public health and the environment in bathing water sites? Let’s look at two technologies, which may bring significant transformation to the sector.

Firstly, molecular biology techniques: primarily Polymerase Chain Reaction (PCR) applications. At the moment, culture-based techniques are used for bathing water quality monitoring (as prescribed by the Bathing Water Directive). These focus on two parameters which act as very useful indicators of sewage pollution or animal waste – E.coli and Intestinal Enterococci – but provide a limited window into the microbial pathogen picture in a particular location.

PCR would allow for testing of a much wider range of organisms, and would therefore provide a significantly more comprehensive picture of microbiological water quality. Additionally, molecular biology techniques could explore new risks that we are becoming aware of; for example the risk of exposure to antimicrobial resistance (AMR). Research has shown that surfers are three times more likely to harbour antimicrobial-resistant E.coli¹ in their guts, highlighting the potential for exposure to AMR through the use of bathing waters.

The second promising technology in this field is artificial intelligence (AI). A number of AI trials are ongoing in the sector, such as a pilot project in Devon² that has combined datasets from local rivers, rainfall and soil with satellite images of local land use, in order to yield water pollution predictions. Wessex Water has also been developing an app for Warleigh Weir to provide information to bathing water users.³ AI technology to predict bathing water quality is in its initial stages, but it provides a promising new avenue for research and development in this sector.

Technological innovation is great, but results also need to be presented in an easy-to-understand manner so that they are useful not just to the specialists, but to the wider public. A key element of either of the above technologies should be the clear presentation of results.

In an era of data openness, bathing water quality information must be transparent and presented in a manner which is accessible and informative to a broad audience, reaching different communities and social groups. This may be in the form of apps, online maps, phone alerts, but should also continue to include physical signage.

An amalgamation of the above innovative technologies – molecular biology and AI – could provide the ideal, unique combination of a comprehensive bathing water quality picture with near-real-time public information.

At the same time as exploring new technologies to monitor the bathing water environment, we all need to continue working towards reducing pollution to all of our water bodies at both the individual and community level.

Let’s enjoy and appreciate our coastal and inland bathing waters, and the huge benefits they provide to our wellbeing; while also investing in innovation to better protect the environment and provide accurate and useful information on water quality to all.

References:
1. Surfers three times more likely to have antib | EurekAlert! and Human recreational exposure to antibiotic resistant bacteria in coastal bathing waters - PubMed (nih.gov)
2. AI to stop water pollution before it happens - BBC News
3. AI technology used for Warleigh Weir bathing water study | Wessex Water

A longer version of this article first appeared in November 2023 in the Foundation for Water Research Newsletter