Thousands of volunteers across England now regularly take out their own testing kits to study the levels of pollution in rivers and the sea.
With sewage spills rarely out of the news, citizen water testing has become one of the most visible responses to England’s pollution scandals.
A crisis of trust in the water companies appears to be driving the public to take water quality testing into their own hands. Thousands of people take part in the twice yearly water testing events, organised by charity Earthwatch. Spring 2025 saw the highest number of participants at more than 7,000. Other organisations also report rising numbers of people getting involved in water testing.
These people, often referred to as citizen scientists, are doing tasks as varied as surveying aquatic insects to sampling water for chemicals.
Much public attention has centred on sewage pollution in UK rivers in the past few years. Waste is regularly and legally discharged into lakes, rivers and along beaches by water companies during periods of heavy rainfall. But incidents of sewage discharges on days with no to low rainfall have also been identified, and in some cases legal action has followed. In some cases water companies have been fined millions of pounds.
The Environment Agency (EA), the main environmental regulator for the water industry, reported nearly 300,000 sewage spills across England in 2025 alone.
The consequences have affected both wildlife and people. Campaign group Surfers Against Sewage documented more than 7,000 cases of illness linked to swimming at official bathing sites over just five years. In 2025, 12 of England’s 14 inland bathing sites were rated “poor”, meaning swimmers were recommended to avoid the water because of potentially harmful bacteria. In April, the UK’s largest pollution claim began to be heard in the High Court, over allegations of chicken waste pouring into rivers along the Welsh-English border.
Public campaigning is believed to have helped trigger recent government action, with reforms expected in a planned Water Reform Bill.
Citizen sceptics
Some water companies now fund freshwater citizen science initiatives. These run across locations including the Thames Valley, south-east England and Wales. The programmes claim to enhance community awareness, empowerment and improve transparency of water companies’ management efforts.
During my PhD, I researched how one group of volunteers in Oxfordshire collected and interpreted river data. Some told me that they felt that water companies encouraged participation in citizen science, while ignoring the data.
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Five warning signs that rivers are polluted – even when they look clean
As one citizen scientist explained in my own ongoing preliminary research, “people keep beavering away, and eager beavers are just what the water industry wants”. In his view, citizen science risks becoming a tool for keeping volunteers busy and distracted, rather than driving accountability.
However, recent research shows water companies have historically underreported the number of sewage spills. The Consumer Council for Water, which represents customers, has reported widespread dissatisfaction with water companies. An independent water commission has also highlighted a deterioration of public confidence in the environmental regulators.
A recent Channel 4 docudrama, Dirty Business, echoes these frustrations. It follows two citizens trying to hold water companies and regulators to account.
In line with some recent academic research, the programme explores suggestions that the water industry attempts to deflect blame and distract attention from sewage pollution. In a statement addressing the allegations, the EA said: “Prosecutions are just one tool against water pollution, and we have also levied a record £8.5 million in enforcement undertakings against water companies in the last year alone.”
Public confidence
The Environment Agency also faces questions about public confidence. Research suggests that volunteers believe current regulations allow water companies to act without sufficient oversight. In this study, people felt that the EA was not fulfilling its responsibility to hold the water industry to account.
In 2024, the head of the EA, Philip Duffy, said that the organisation had buried freedom of information requests, with staff worried about revealing the embarrassing truth of water pollution. In a statement reported in the Guardian at the time, the EA said: “Philip is completely committed to the highest standards of transparency.” It added that he wanted to make more EA data readily available.
In January 2026, the Office for Environmental Protection, a public watchdog on environmental protection, also found possible failures by the EA to comply with water quality laws.
My participants felt that the agency shouldn’t ignore their data in monitoring water quality.
Concerns about data bias and reliability are often cited as reasons to limit the use of volunteer data to support regulatory responses to pollution incidents.
These concerns are not unreasonable. Citizen science data can indeed vary in quality, depending on training and sampling practices. Ensuring consistency across the sheer number of volunteer groups is also a challenge.
Using citizen science
Nevertheless, research now suggests volunteers can produce reliable data suitable for official monitoring. The debate is gradually shifting to how regulators can include it in decision-making. For example, a national programme has already developed a shared framework on how to use data collected by citizens.
In the meantime, groups such as environmental charity Earthwatch and Surfers Against Sewage design and publish their own online maps and dashboards. These make thousands of historic data points publicly available.
As summer arrives and 13 new bathing sites open, pressure is again mounting on water companies and regulators to clean up England’s rivers and beaches. The citizen water sample collectors will be on standby.
