River Pollution & COVID-19

The Pollution Problem

UK rivers are becoming increasingly polluted with untreated sewage which can contaminate waterways with millions of microbes. The contaminated water can also contain wet wipes, tampons and condoms that people flush down their household loos. There are no bathing standards applied to any of the rivers in the UK, so water companies have been excused of any responsibility to maintain and monitor sites for public use. Not only does this have an enormous impact on wildlife, it also presents associated health risks to recreational river users all over the country.

“Bathing water standards are applied to the coast at 400 sites. These sites must meet microbiological standards for water quality, whereas there are no standards in place for bacteria and viruses in UK rivers. We want to see these standards for rivers so that recreational swimmers to have a better idea of health risks.”

Doctor Rob Collins, Director of Science and Policy at the Rivers Trust

The untreated sewage originates from Combined Sewage Overflows (CSOs), which collect rainwater and household wastewater and deposit it straight into the river. These systems are intended as a pressure valve, to be used sporadically to prevent blockages and backups. There are 18,000 of these CSO pipes in the UK and 90% of these drag a combination of sewage and rainwater into our rivers [1]. Despite being intended only for intense rainfall events, a study in the Guardian revealed that these CSOs released raw sewage 204,134 times during 2019 [2].

The Environment Agency permits water companies to flush sewage into rivers after extreme weather, however they are subject to an investigation if more than 60 sewage discharges are made a year. The Guardian’s data suggest that water companies exceed this limit, yet because they are relied on to self-monitor their river discharges, inaccurate reporting is rife [2].

The sewage dumped in rivers is untreated and the levels of E. coli, for example, can be between 1,000 and 10,000 times higher than properly treated wastewater [3]. Swimmers in Chester became ill after swimming in the polluted waters of the River Dee only last month (June 2020). The swimmers were reported to have diarrhoea, fever and abdominal pain requiring medical attention [4].

The Risk of COVID-19

The SARS-CoV-2 virus that has caused the recent COVID-19 pandemic has a longer persistence in stool samples and so patients that tested negative in the throat swabs, may still have the virus present in their faeces [5]. It is not yet known if faecal to oral transmission of the virus is possible, but waste should be carefully dealt with in order to prevent possible infections [6].

Because so many people may only experience mild symptoms of the novel coronavirus, it is not just hospital waste which must be managed, but all household waste [6]. People who have previously recovered from the virus and are completely asymptomatic were also found to have traces of the virus RNA in stool samples [5].

“It is not yet known whether the virus can be transmitted via the faecal-oral route, however, we know that viral shedding from the digestive system can last longer than shedding from the respiratory tract. Therefore, this could be an important – but as yet unquantified – pathway for increased exposure.”

Professor Quilliam, environmental biologist at the University of Stirling [7]

The UK Centre for Ecology & Hydrology (UKCEH) are currently undertaking a research project into whether sewage surveillance can be used as an effective test to detect outbreaks of infectious illnesses such as COVID-19 before symptoms occur. They also hope their investigation will confirm whether SARS-CoV-2 found in sewage poses an infection risk [8].

Computer generated image of a coronavirus (public domain)

Take Action For Rivers

With the rise in “staycations” the government is promoting, there may be more people flocking to waterways with kayaks this summer than in previous years. The ‘Together for Rivers’ campaign, run by the Rivers Trust, seeks to introduce bathing standards for rivers in the UK. They are introducing a comprehensive national monitoring programme for microbe sampling which can then be used to determine the safety of our rivers.

“Over time [the monitoring programme] will tell us what the bacteria levels are and whether the rivers are safe to swim in. If the levels are high, the next step is to look at why that is and what the sources of those microbes are, for example sewer overflows, septic tanks or grazing animals. It flags problems and identifies where there are potential sources.”

Doctor Rob Collins, Director of Science and Policy at the Rivers Trust

The monitoring sites emerge when local community groups recognise there is a problem with microbial pollution and contact the Rivers Trust to set up a programme. Monitoring is already taking place at Ilkley in Yorkshire, where residents are using their findings to support campaigns. They are currently working on decombining the sewage system from the rivers so that the storm overflow at Addingham and Ilkley only discharges sewage when it actually storms and not every day it rains. You can find out more about their work on their website here.

[In Ilkley,] we have a citizen science protocol, the first in the UK, and the work is lead by our own Prof Rick Battarbee. Samples are taken using this protocol and taken to a Lab approved by the Environmental Agency for analysis. We pay for the analysis from a grant from the Town Council.

Professor Becky Malby, Resident and volunteer at Ilkley Clean River

You can check whether your rivers are downstream of CSO by using their interactive map that you can find here [9]. Currently the map only shows CSOs but the Rivers Trust aim to update it with information about other sources of microbial pollution in the future. Concerned community groups and swimming societies can get in contact with the Environment Agency or their local water company. To ensure that our UK rivers are unpolluted for both wildlife and recreation, Surfers Against Sewage have set up a petition to reduce sewage pollution along with a coalition of other organisations like the Rivers Trust. Please consider donating or signing their petition here [10].

The Rivers Trust (@theriverstrust) | Twitter

Thank you to Doctor Rob Collins from the Rivers Trust for agreeing to be interviewed on this topic and for giving such a great overview of their monitoring programme and the Together for rivers campaign.

Thank you to Professor Becky Malby from the Ilkley Clean River project for taking the time to answer questions via email regarding their pioneering river monitoring project.


[1] https://www.wwf.org.uk/updates/40-rivers-england-and-wales-polluted-sewage
[2] https://www.theguardian.com/environment/2020/jul/01/water-firms-raw-sewage-england-rivers
[3] Honda, R., Tachi, C., Yasuda, K. et al. Estimated discharge of antibiotic-resistant bacteria from combined sewer overflows of urban sewage system. npj Clean Water 3, 15 (2020). https://doi.org/10.1038/s41545-020-0059-5
[4] https://www.cheshire-live.co.uk/news/chester-cheshire-news/public-health-warning-after-swimmers-18502117
[5] Ling Y, Xu SB, Lin YX, et al. Persistence and clearance of viral RNA in 2019 novel coronavirus disease rehabilitation patients. Chinese Medical Journal. 2020 May;133(9):1039-1043. DOI: 10.1097/cm9.0000000000000774.
[6] Quilliam, R. Weidmann M. Moresco V. et al. (2020) COVID-19:The environmental implications of shedding SARS-CoV-2 in human faeces. Environment International Vol 140, 105790 https://doi.org/10.1016/j.envint.2020.105790
[7] https://www.stir.ac.uk/news/2020/05/sewage-poses-potential-covid-19-transmission-risk-experts-warn/
[8] https://www.ceh.ac.uk/press/work-begins-uk-system-estimating-covid-19-cases-wastewater
[9] https://www.arcgis.com/apps/webappviewer/index.html?id=a6dd42e3bc264fc28134c64c00db4a5b&extent=146436.9576%2C27590.8012%2C854242.0922%2C563326.0668%2C27700
[10] https://www.theriverstrust.org/2020/07/01/new-campaign-aims-to-see-bathing-water-standards-introduced-to-uk-rivers/