Ilkley Clean River Group                            WQR0084


Written evidence from Ilkley Clean River Group


Prof Becky Malby, RSA Fellow lives in Ilkley and works at London South Bank University as a Professor of Health Innovation. She is a co-founder of the Ilkley Clean River Group, which was set up out of the frustration of some Ilkley residents with the lack of response to continued reporting of sewage discharges into the river Wharfe at Ilkley. What we found sparked national interest and 2.5 years later we achieved the first river to be awarded Designated Bathing Status, a citizen science protocol for testing river water quality, and have been promised action to clean up the river. We have shown that sewage discharges are normal and regular practice; that despite the agencies assertions that everyone knows it’s happening; the public are actually outraged about it; and that these sewage discharges are a threat to people’s health and to the ecology of the river. The Ilkley campaign has attracted national media attention capturing the nation’s mood in terms of protecting our environment, securing best value for our communities and seeking accountability from agencies. From January 2020 – March 2021 our campaign has been covered by BBC news and Countryfile, Channel 4 News, The One Show, the World at One, Women’s Hour; has featured in The Guardian multiple times, in The Times, the Financial Times, as well as regional and local newspapers.

Restoring the river in Ilkley and beyond

We are seeking sewage facilities for Ilkley that only discharge raw sewage compliant with the European Urban Waste Water Treatment Directive, (extreme weather); which do not discharge sewage solids into the river or onto the riverbank; basic ongoing maintenance of the sewage infrastructure.

The Campaign

We have worked to:

  1. Understand what’s really going on – (a) data – through our citizen science on microbiological water quality, (b) FOI and requests to secure storm overflow frequency, (c) collaboration with Yorkshire Water to investigate infiltration and pollution sources.
  2. Hold the agencies to account for the real situation we are facing through Town Meetings and the media.
  3. Secure Bathing Status as a means to catalyse regular water quality testing for feacal bacteria and a clean-up.






  1. Context: The River at Ilkley

On hot sunny days over 1000 people use the river at Ilkley for recreation.

Figure 1: the river at Ilkley in the Designated Bathing Status Application showing the distinct stretches of usage.











  1. Understanding What is Really Going on

(a)     The extent of storm overflow discharges at Ilkley

The sewage works at Ilkley continues to discharge raw sewage into the river at Ilkley when it rains. YW reported 123 days of sewage discharges in 2018, 201 discharges over 114 days in 2019. For 2020 we are verifying the data from Yorkshire Water but it looks like 120 days with discharges, only 10 of which were in heavy rainfall (with thanks to Peter Hammond). Our data shows 8mm of rain can trigger a storm overflow discharge of raw sewage into the river.

According to the SOAF (Storm Overflow Assessment Framework) 40 ‘spills’ a year over 3 years or >60 spills a year should trigger the SOAF requirements for investigation and solution finding (a 15-year process).

The EA did not know the extent of the ‘spills’ (raw sewage discharges) at Ilkley because their water monitoring was not triggering investigation of the spill frequency.  Yorkshire Water knew about the frequency (they provided us with the data) but was not required to report it.

All reported incidents were legal under the Consent Limit for the treatment plant at Ilkley set 18 years ago.

The Wharfe was apparently under the radar until our campaign.

(b)     Water quality

The EA claimed the water is in good condition, (as set out under the Water Framework Directive) at our first Town Meeting (February 2019), then subsequently confirmed it is Moderate. Our own review of the data shows it is Moderate.

(a) The EA monitors for nutrients.

(b) No-one monitors the faecal bacteria concentration in sewage effluents, either treated or untreated. 

We pressured the EA into monitoring water quality at Ilkley which they instigated monthly in 2019 for a 12-month period upstream and downstream of the sewage treatment works, but they did not include faecal bacteria monitoring. Prof Rick Battarbee from the ICRG developed the UK’s first Citizen Science river testing protocol for faecal bacteria and put it into action. This demonstrated the severity of the pollution coming both from treated and untreated sewage effluent discharges

The EU Bathing Water Directive 2006/7/EC provides the following 90 percentile values for faecal bacteria in water of sufficient quality for bathing 


Excellent quality1


Intestinal enterococci (cfu/100 ml)



Escherichia coli (cfu/100 ml)



As you can see from our testing when the river is in low flow the river quality far exceeds this minimum standard downstream of the sewage works (i.e. treated sewage outflow). In low flow conditions, high concentrations are caused by faecal bacteria from the treated effluent.


In high flow the whole of the river is a public health hazard

Upstream tributaries, especially those in Addingham, also contain high concentrations of faecal bacteria (and nutrients) from livestock and septic tanks (yellow) causing poor water quality in the becks in turn contributing to the pollution load on the main river through Ilkley. We found that upstream sewage sources (from the village of Addingham) were more important than agricultural sources, although agriculture caused high concentrations in tributary streams.