Ashley Smith - Windrush Against Sewage Pollution                            WQR0069


Written evidence submitted by Ashley Smith, Chair of Windrush Against Sewage Pollution, a campaigning group seeking an end to water industry pollution.

Executive Summary

Four years of investigation and analysis of sewage treatment and pollution by Windrush Against Sewage Pollution volunteers, mainly in the Thames Water Area, has revealed evidence of extensive under performance of sewage works, sewer networks and the regulatory process in respect of pollution by untreated sewage. It appears that a great deal of this is caused by groundwater infiltration which the Environment Agency regards as an unpermitted activity and this renders the action illegal.

The tankering of sewage between catchments may conceal failures in infrastructure from Ofwat and put off investment and improvement.

Requirements made by the Agency for the industry to classify and rectify storm overflows starting in May 2018 were totally ignored, something which probably saved the industry billions of pounds.

Environment Agency and water industry staff move between organisations in a way which would be healthy in many situations but potentially not when one key function is the investigation and prosecution of serial criminal pollution offences by the industry.

The regulatory control of the industry appears to have been degraded steadily since privatisation including the introduction Operator Self-Monitoring in 2010 and is now so weighted in protecting the industry from requirements to address failure that the industry has become reliant on sweating the assets and relying on often unpermitted pollution to protect itself from expenditure and to achieve successful annual assessment results.

The Water industry has successfully influenced regulation to the point where it now chooses what regulation to obey and how to adjust it to suit its aims.



  1. Many of the lengthy spills of untreated sewage which continue long after rainfall events are caused by elevated groundwater levels (admissions and explanations from Thames Water and EA) infiltrating sewers at joints and breaks, etc. The subsequent volume overload means that untreated sewage spilling has to take place so that STWs can continue to treat effluent to permitted levels and discharge the two substances, treated and untreated sewage, side by side or mixed. It is only the permitted effluent that affects the Environmental Performance Assessment where we can see Thames Water achieving 99.7% success in 2019, for example. Water and sewerage companies in England: environmental performance report for 2019 - GOV.UK ( The untreated sewage spills which may often be in progress when the successful samples are taken do not affect the EPA. In 2009 Thames Water spilled untreated sewage for about 109,000 hours – EA and TW data.
  2. WASP has, since late 2019, been asking the EA to apply the law in respect of spilling due to groundwater infiltration which is not a permitted activity. Water pollution is illegal unless it is permitted so, based on the EA assertions, this type of pollution is against the law. Environmental Permitting (England and Wales) Regulations 2016.


  1. Quotes to support this position:


  1. From the ministerial contact office replying on behalf of SoS, George Eustice in September 2020 and in answer to WASP questions about this subject.


‘If the EA identifies and has evidence that sites are making discharges at non-storm times due to infiltration it will regulate to prevent this and there will be a corresponding enforcement response in accordance with its enforcement and sanctions policy.


  1. From Sir James Bevan in June 2020, responding to Sir Geoffrey Clifton Brown MP asking on behalf of WASP about a range of issues including ‘storming’ from STWs and SPSs.

‘This can only be carried out in line with permit conditions, which are designed to ensure the impact of any discharge to the environment is low. It can only be carried out due to rainfall or snowmelt. Discharges of untreated sewage due to groundwater infiltration alone are not permitted.’

  1. From EA Area Director, Julia Simpson to the Upper Thames Fisheries Consultative in July 2019

‘We expect water companies to identify and take action to minimise infiltration into their sewers.  Storm discharges due to excessive infiltration is not a genuine or permitted reason for a storm discharge.  We will take action in line with our enforcement and sanction policy where this is identified and causes environmental impact’.

  1. Evidence of spilling due to groundwater infiltration is extensive and widely admitted by Thames Water. Examples available at Witney, Brize Norton, Standlake, Northmoor, Clanfield Bourton on the Water and many others. Whilst the Agency claims to be investigating some offences but will not reveal which, it fails to prevent or address the repetition of the same circumstances.
  2. In 2014 following determined efforts by the Upper Thames Fisheries Consultative, the EA finally challenged long term spilling of untreated sewage from Witney Sewage works into the Colwell Brook, a tributary of the River Windrush. The pollution was so extensive that sewage fungus was prevalent in the 1.6km of the brook. The cause was established as groundwater infiltration and Thames Water undertook to prevent the situation arising again but later went back on that agreement. The response of the Agency was to do nothing but to note that in that case they would prosecute the next time it happened.
  3. No monitoring measures were put in place and it was not until November 2019 that WASP discovered and reported a similar long spell of pollution so extensive that it caused sewage fungus throughout the whole brook. Eventually the Agency agreed to investigate the offences which continued almost non-stop into the start of April 2020. Even though this investigation is apparently under way, Thames Water has done little or nothing to prevent a recurrence and the Agency has not intervened. It may be powerless in this respect.
  4. In 2021 we are yet again recording and reporting similar pollution incidents at the same place.


  1. In addition and also as a contributor to untreated sewage spilling, the tankering of sewage by road from flooded sewers can also increase the pressure on STWs. The lengthy, disruptive and carbon heavy tankering operations suffered by residents in many areas are often caused by such infiltration.


  1. Recent communication with the Environment Agency and Thames Water revealed that there is no current EA guidance on the transfer of sewage between catchments, to STWs already overflowing to a watercourse or sea, or to prevent the manipulation of compliance results. This was an activity which was a major factor in serious offences for which Southern Water was recently prosecuted. In the absence of an authoritative document, the Agency had to resort to compiling some unattributed comments (available) to respond to my EIR request and when I asked for validation of the information I received the following:


  1. Email from EA Customers & Engagement Team - Thames 21st Jan 21 - Thank you for your email of 20 January 2021. The response to THM157663, THM199368 and THM199567 was written in the Thames Area with technical input from national Environment and Business Water Quality. The response was written in the context of your enquiries and the various circumstances where Thames Water Utilities Limited carry out tankering on their network and at sewage treatment works. The response reflects the positon in the Thames Area and we understand this position is also consistent with the national Environment Agency position.


  1. I await confirmation from an EA Area Director that this unlikely explanation is correct. The seriousness of this omission should be very clearly demonstrated by this document. Ofwat’s final decision to impose a financial penalty on Southern Water Services Limited

Note S4.12 in particular.

  1. in the case of a village near to Weston on the Green in Oxfordshire, a tankering operation continued 12 years to empty flooded sewers. A BBC report at the time read: ‘Tankers have been in the village working round-the-clock to pump out the excess, a move Thames Water says is more cost effective than working to put the problem right.’ Oxfordshire village of Caulcott suffers ongoing sewage problem - BBC News There are many other examples of current activity.
  2. Twice I have heard senior Thames Water Executives say that the business model encouraged by Ofwat’s approach to the industry had been one based on ‘sweating the assets and there is ample evidence to back this up’ as above and in may similar cases.
  3. The resistance of the industry to investing to solve failing and illegal assets can be clearly demonstrated by its failure to apply a potentially effective piece of guidance published by the Agency in May 2018.

Extract from guidance Water companies: environmental permits for storm overflows and emergency overflows - GOV.UK (

Classify storm overflows for improvement

As a water company, you must design, construct and maintain sewerage systems according to best technical knowledge not entailing excessive cost (BTKNEEC). You must also limit pollution from storm overflows. To make sure you do this, you must identify storm overflows that need improvement.

You must classify your storm overflows as either:

Do this as part of your drainage strategy. Identify where investment is required. Read Ofwat’s guide on how to prepare a drainage strategy.

Unsatisfactory overflows

The Environment Agency classes storm overflows as unsatisfactory when they:

  1. Correspondence with Thames Water revealed that the company had not complied the guidance in any way. Enquiries with the other utilities revealed a similar response with some at least trying to bring in coincidental work to apply to the requirement.
  2. Yorkshire Water’s response stood out: To be clear, there is currently no obligation on water companies to follow the EA or OFWAT guidance, or to classify all storm overflows.
  3. When challenged by WASP about the failure of Thames Water to comply with the guidance the Agency stated that it had no legal requirement attached to it so it didn’t matter. Of course this applies to all Agency guidance and the guidance was an instruction to address overflows which did not comply with the law in some cases. Supporting E mail correspondence with Thames Water, Environment Agency and Ofwat is available.
  4. Even a cursory look at the guidance will indicate that, should it have been implemented, the industry would now be well on the way to fixing many of the problems that have brought us to this critical state. However, it would probably have cost the industry billions of pounds if current estimates are to be believed.
  5. Further research reveals the industry has apparently been looking for a way out of this expensive requirement which has been conveniently set aside by the EA and that has come with the subsequent writing of the Storm Overflow Assessment Framework SOAF.pdf ( (a cursory glance will show it to be hugely biased in favour of doing nothing that will cost the industry money and will perpetuate and legitimise failure and pollution).
  6. To continue on this theme, another piece of work is looming; the Drainage and Waste Water Management Plans, designed by consultants commissioned by the industry in ‘collaboration’ with Defra, and the EA Water_UK_DWMP_Framework_Appendices_September-2019-A.pdf and designed to sweep away the Drainage Strategies which replaced the Infiltration Plans which were specifically designed to address infrastructure failure but were allowed to slide.  This latest development represents the industry deciding on how it wants regulation to apply and that means a way to perpetuate and profit from pollution.
  7. The revolving door of employment between the water industry and Environment Agency may be a healthy state in some types of employment but in the case of water quality, investigation and monitoring roles this is predictably fraught with conflict. That may manifest itself in the pressures of previous working and social relationships, or anticipation of future employment in the industry and there appears to be little evidence of any control or support measures applied by the EA other than the vague application of declarations of conflicts of interest. Obtaining detailed information in respect of this and water industry share ownership or conflicting business interests via the EIR has met with a slow and unhelpful response from the EA and it does appear that the Agency lacks any meaningful monitoring or support mechanism in respect of staff vulnerable to pressure and influence.
  8. In 2017 after the successful prosecution of Thames Water resulting in the £20m fine, the company recruited at least one of the EA investigation and prosecution team. At least one of the very few members of the depleted EA investigation and enforcement team is a former Thames Water employee. In 2020 the EA Director of Operations was recruited to a newly created role by Southern Water whilst the company was being investigated and prosecuted for serious offences by the Agency, an activity in which the director was likely to have had a key role. The same Director had been allowed to be a non-executive director of British Water, an industry lobbying body since 2019. FOI and EIR questions about this publicised situation have been ignored by the EA.
  9. Regarding Environment Agency regulation; When I asked an EA Area Director how frequently the EA inspected sewage works, she told me it could be every few days, weeks or even months. She even agreed it could be over a year in low risk locations but the truth we later discovered was that the target for the EA inspecting STWs in the Thames Region was on average on a ‘risk based’ system was once every 8 years. That meant that in 2017 that 33 inspections were required but in reality 17 were carried out from a total of around 364 STWs.
  10. Our scrutiny of inspection of a small number of inspection documents (available)revealed that Agency inspections are pre-arranged and the recommendations from Agency staff are easily ignored without consequence. In one case, within about two years of an EA inspection, WASP discovered an undeclared and unpermitted ‘storm’ overflow at Bourton on the Water that had been missed by the Agency for many years and had not been revealed by Thames Water. The consequences for Thames Water concealing that? – none.
  11. Add to this that the EA will accept the impact assessments of the polluter as we witnessed at Bourton on the Water in 2019 - documents available - and appear to accept without question, assessments made by Thames Water’s independent consultants, OHES Environmental whose website states under the heading; Spill Response‘In over 8,000 incidents we have NEVER had a client prosecuted for causing pollution where OHES managed the initial response.’ 
  12. The acceptance of assessments from organisations with a vested interest in concealing the truth has consequences and such an example appears to have happened in 2016 at Witney STW. About 1700 fish died in an ammonia pollution emanating from Witney STW and the event was ‘investigated’ by the Environment Agency. Thames Water claimed that a substance had passed through the STW from an outside source and had contained high ammonia levels which killed the fish. The substance was not identified – as in none was found and nor was the source, but the Agency accepted the explanation when there was clear evidence that there were processing problems occurring at the STW. Requests to view the records of the EA decision making process were resisted.


  1. The incentives developed around the industry at present are negative. Polluting is cheap and profitable and it is easy to evade capture and even easier to evade prosecution. Untreated sewage pollution is the end result of many failures including those which result in the flooding of people’s homes and long term tinkering disruption as well as widespread pollution and risk to public health. A simple and effective volumetric monitoring and charging scheme per litre of untreated sewage, with an incentivising and increasingly severe tariff would plug in to what private industry does well – develop solutions that will save or make money. The industry would pay an attention grabbing fee to pollute and it would become cheaper and more profitable to do the job properly, legally and well. Accepting that there would have to be vigilance for cheating the process, pollution would end.
  2. Similar tariffs could be placed on damaging substances like phosphate in treated effluent, with a similar effect.

AS 5.2.21


February 2021