The Question Every Wild Swimmer Has Asked
Anyone who has ever plunged into a river, lake, or coastal inlet has probably had that nagging thought at the back of their mind: what exactly is in this water? It is a perfectly reasonable question, and increasingly, wild swimmers, dog walkers, and open-water enthusiasts across the UK are no longer content to simply wonder. They are taking matters into their own hands and finding out for themselves.
A growing grassroots movement of community water testing is sweeping the country, with ordinary people — from weekend wild swimmers to concerned dog owners — collecting water samples from their favourite spots and demanding greater accountability for the quality of our rivers, lakes, and coastline. It is citizen science at its most powerful, and it is making a real difference.
Why Water Quality Matters More Than Ever
The UK’s rivers and lakes have faced mounting pressure in recent years. Agricultural run-off, sewage discharges, and urban pollution have all contributed to declining water quality in many well-loved swimming spots. Whilst some areas have seen genuine improvements thanks to conservation efforts, others continue to struggle — and official monitoring alone is not always enough to paint a complete picture.
For wild swimmers, the stakes are real. Poor water quality can expose you to a range of harmful bacteria, including E. coli and Enterococcus, as well as potentially dangerous blue-green algae (cyanobacteria). Dogs are particularly vulnerable too, since they tend to drink the water as they swim and are less likely to notice warning signs. Symptoms of exposure can range from an upset stomach and skin irritation to more serious illnesses in severe cases.
The good news? Testing your water does not require a laboratory or a science degree. Reliable, easy-to-use test kits are now available that allow anyone to get meaningful results from their local swimming spot in a matter of minutes.
What Community Water Testing Actually Looks Like
Across the UK, communities are banding together to monitor their local waterways with impressive results. Local swimming groups, conservation volunteers, and passionate individuals are collecting regular samples, logging data over time, and sharing findings with local authorities and environmental organisations. This kind of sustained, community-led monitoring is invaluable — not just for swimmer safety, but for holding polluters accountable and building a detailed picture of water health across different seasons and weather conditions.
Rainfall, for example, can dramatically affect water quality. Heavy rain washes pollutants from farmland and roads into watercourses, and can also overwhelm sewage systems, causing overflows. Knowing how your swimming spot responds to different conditions is knowledge that only comes from regular, consistent testing.
Getting Started with Water Testing
If you are inspired to test your own swimming spot, the process is more straightforward than you might think. Here is what you will typically want to assess:
- E. coli levels — a key indicator of faecal contamination and sewage pollution
- Enterococcus bacteria — particularly relevant for bathing water safety assessments
- Nitrates and phosphates — signs of agricultural run-off that can fuel algal blooms
- pH levels — extreme acidity or alkalinity can indicate pollution and affect wildlife
- General water clarity and temperature — useful contextual information when logging results over time
Many swimmers choose to test before each swim session, especially after periods of heavy rainfall or if they notice any unusual smells, colours, or surface films on the water. Building up a log of results over weeks and months gives you genuinely useful data — and the confidence to make informed decisions about when to swim and when to give a spot a miss.
Sharing Your Results
Testing is most powerful when results are shared. Consider logging your findings with organisations such as the Rivers Trust, Surfers Against Sewage, or your local wild swimming group. Many communities have set up their own shared spreadsheets or use dedicated apps to pool data and spot patterns. Your results could help protect other swimmers — and your four-legged companions — from harm.
Swim Informed, Swim Confidently
Wild swimming is one of the most joyful, invigorating things you can do in the UK’s great outdoors. There is nothing quite like the freedom of an open lake on a summer morning or the bracing clarity of a chalk stream. But that joy is best enjoyed with your eyes open — and your water quality data to hand.
Whether you are a seasoned open-water swimmer, a dog owner concerned about your faithful companion’s health, or simply someone who wants to understand the waterways around you better, testing your water is a brilliant first step towards safer, more informed swims.
Ready to get started? Browse our full range of water quality test kits — designed specifically for wild swimmers and open-water enthusiasts — at wildswimmingtests.co.uk/shop. Find the right kit for your needs and take the guesswork out of your next swim.
📷 Photo by Jaz Blakeston-Petch on Unsplash
