Natural Water Quality and Pollution: The Impact on Human Health and Testing

In the first part of this two-part series, we looked at the impact of sewage spills on the UK’s natural waterways, and in particular, how such spills affect water quality. With some 1.75 million hours of spills in 2022 – more than doubling in 2023 – this clearly has a significant impact on the quality and safety of the natural water sources around us.

In this second article, we’re going to look at how pollution and sewage spills can affect human health, and how water testing plays an important role.

Can water testing identify the chemical and ecological health of rivers?

Water sampling and testing can tell us whether any pollutants are present in a river, along with looking at how many natural species are present. According to the Rivers Report 2024 from The Rivers Trust, this can tell us a lot about the overall health of a river.

As we noted in part one of this series, rivers are split into separate river stretches. This means one stretch of a river could potentially be healthier than another – something that is more likely to happen upstream. Unfortunately, 85% of river stretches throughout England do not meet good ecological standards.

River sampling allows experts to test the water to find out what’s in it. Unfortunately, 2022 data showed that river stretches where water was sampled for testing were down by 6% on three years before (data is collected on a three-yearly basis).

Rivers fail for all kinds of reasons, some of which are currently unknown, so it’s not all down to sewage spills. Indeed, 54% of river stretches did not meet standards because of activities undertaken by the water industry (including sewage spills). However, 62% of river stretches were noted to be polluted by agricultural and rural land management processes.

And it’s not just the health of the river that is worrying in this situation. Anyone electing to swim in a river or other natural water course is potentially at risk too.

The impact of poor water quality on human health

Thousands of people head out to popular bathing spots throughout the summer, enjoying getting into the water for a swim. However, the Environment Agency only monitors the most popular swimming locations. These are called bathing waters, and largely cover coastal locations and a handful of lakes rather than rivers. While rivers are managed, they are typically done so to make sure fish and wildlife are safe rather than humans.

85% of river stretches throughout England do not meet good ecological standards

This means river water is not tested to ensure humans can safely swim in them. Bathing water testing looks for the presence of two types of bacteria:

• E. coli
• Intestinal enterococci

These come from faecal matter and may therefore present a significant risk to human health if anyone swims in those waters.

Is it safe to go wild swimming in rivers?

You won’t be surprised to find out that deciding how safe it is to swim in a river depends on the river itself and on the conditions therein. In part one of this article, we learned that water companies can legally release sewage into rivers when there is heavy rain. Doing so means that there is less risk of homes in that area becoming flooded. Hence why a year that sees heavy rain will automatically see a higher rate of sewage spills. This occurs because in the UK, sewage uses the same network of pipes filled with rain during a storm or period of wet weather. This means that there is a good chance a river will be unsafe to swim in after it has rained.

Some wild or open water swimming spots are going to be safer than others. For example, if you’re up in the mountains and you find a plunge pool or waterfall feeding into a river that comes off the mountains, it’s probably going to be clear and much safer to use. However, downstream, that river might well run past farming land, and that could be polluted making it unsafe nor desirable to swim in.

Some aspects of river swimming involve assessing the local currents and the immediate surroundings. Are there any trees nearby that look unstable that could fall into the water, for example? When it comes to bacteria in the water, you cannot easily tell whether there is anything to be worried about. It’s possible to buy tests to use yourself before getting into a river for a wild swim, but even then, the water is moving. The spot you test could be fine, but you may swim out into an area with increased bacteria in it and you wouldn’t know.

Then there’s algae. Any green or blueish bloom on the water marks out a spot that should be avoided. That should be easy enough to see when you are viewing the surface of the water, but again, bacteria aren’t visible to the naked eye.

How can waterborne bacteria make you ill when swimming in rivers?

E. coli bacteria typically generate symptoms three to four days following infection. However, it can be sooner or later than this. It presents as a stomach upset, with diarrhoea and cramping. The diarrhoea may have blood in it. If you experience such symptoms following a river swim, contact your GP to seek advice. Mild cases usually resolve without treatment, but prolonged diarrhoea can cause dehydration. E. coli can also cause UTIs.

The bottom line here is that if you want to experience some wild swimming, you’re better off going to one of the recognised and tested bathing waters in the UK. You can visit the Swimfo website (part of DEFRA, the Department for Environment Food and Rural Affairs) to find out more.

When wild swimming in rivers, it’s clear that sewage spills are just one of the challenges you need to face. Many wild swimmers speak to locals to find out where the safer spots are. However, the risks will always be present. It’s certainly true that lots of people do go wild swimming each week and do not experience any negative effects – quite the opposite.

The bottom line is that the water quality in rivers across England – and indeed the UK – has a long way to go to improve. There are many challenges here, so those wishing to wild swim would be far safer to stick to one of the recognised bathing waters, which are largely in coastal locations.

Expert water quality testing for natural water sources

Water Treatment Services offer a comprehensive range of water quality testing and laboratory analysis solutions for natural water sources.

Our experts can provide advice and support to help you identify strategies for the safe management of your natural and recreational waters.

With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of specially trained technicians, in-field specialists and consultants we can offer professional, cost effective water quality testing and laboratory analysis solutions across the whole of the UK and internationally.

Contact us today to learn how our expert water quality analysis services can help you keep your water safe.