You can download a copy of the letter we sent to the EA here:







EA response:

Our reference: THMCU4244


Dear Mr Smith,


Thank you for your email of 23 July 2019 attaching a letter, to our

Chief Executive, Sir James Bevan, regarding the River Windrush. James

has read your email and letter and asked me to respond on his behalf.

He will receive a copy of this response.


I am aware of numerous meetings and correspondence between your

campaign group, Windrush Against Sewage Pollution (WASP) and our local

officers about your ongoing concerns on the state of the River

Windrush. I am also aware of the recent story on the BBC South today

news bulletin. Our statements to the BBC were provided on the basis of

the evidence we have to date and referred specifically to the

monitoring at Bourton-on-the-Water. How the BBC choose to relay our

statement is wholly within their remit.


As you know we have been asked to provide information about storm

sewage discharges at Bourton-on-the-Water and separately about

turbidity on the River Windrush more widely. It is important to

recognise that these are very likely to be different issues.


I think it is very important not to conflate storm sewage discharges

with the turbidity witnessed on parts of the River Windrush. Our

position is that these are separate issues. We understand your

concerns about turbidity and do not rule out the influence that

treated effluent from the various wastewater treatment works or

phosphate levels – which can come from sewage as well as other sources

– can have on the River Windrush.


We recognise that the River Windrush has appeared turbid for longer

periods of time in the last few years and understand your concerns

about this. However, whilst the causes of this may not be fully

established and there may or may not be a link with treated sewage

discharges, we do not believe the turbidity is the direct result of

storm sewage from the wastewater treatment works on the Windrush.


There have been many previous studies looking to understand the causes

of turbidity in the River Windrush. Currently the evidence we have

collated to date suggest that the turbidity was most likely to be

inorganic calcite precipitate from the underlying geology and that

flow conditions play a part in this. We are undertaking further

investigations to help understand the situation in 2019. We retain an

open mind about the causes of turbidity but evidence from these

studies, the fact that we are in a period of prolonged dry weather and

the absence of indicator pollutants of storm sewage (e.g. ammonia),

lead us to believe that storm sewage discharges are not the cause.


We are an evidence based organisation and use the information and data

available to us to inform our understanding of the situation. We

cannot depart from what the evidence shows, but we will keep an open

mind in terms of the many challenges and pressures the River Windrush,

like all rivers in England, face. We also recognise that our evidence

is subject to the limitations and extent of our monitoring network. At

the same time as recognising that the evidence we have is limited to

the geographical extent throughout the whole River Windrush catchment.


The evidence we have does not show the river to be seriously polluted

with sewage, nor does it show it to be in state of rapid decline. Our

evidence consists of the previous studies on turbidity of the River

Windrush and extensive monitoring data we hold, alongside water

quality readings taken in the field and laboratory analysed water

samples. This information is publically available and officers have

continued to reply to your enquiries and have, I understand, provided

you with any information you have requested. If there are any

enquiries you have made which you believe have not been answered,

please let me know.


We have told you that our officers have recently carried out

additional sampling on the River Windrush. We have already committed

to share the results with you.


I can confirm that the results received to date have not identified

anything that changes our understanding of the cause of the turbidity

of the River Windrush. It has indicated generally good water quality

along the length of the River Windrush for parameters that would

normally be affected by sewage pollution. An increase in turbidity was

detected in the lower reaches of the river but his was not accompanied

by a change in other parameters associated with sewage. This means we

can be confident there is no acute sewage pollution causing the

discolouration of the River Windrush. The more recent water quality

sampling has indicated potentially elevated iron levels which we are

looking into further.


Through monitoring over the long-term we have identified various

issues that do affect the River Windrush. This includes the presence

of phosphate which modelling indicates is linked to point source

discharges from the water industry as well as from other sources such

as diffuse agricultural pollution. We are constantly driving for

improvements to these known issues to try and prevent any

deterioration of the River Windrush and to work towards delivering

Water Framework Directive objectives.


We have always said we will keep an open mind on the cause(s) of the

turbidity but this is subject to the evidence we have available. We

will continue to share the results of future monitoring with you in

the same way as we have provided all of our historic data. We would

welcome and consider any evidence or information WASP, or any other

party, provide in terms of any water quality issues in the River

Windrush. We wish to work constructively together with WASP and

others to protect this valuable watercourse.


I understand you discussed the results from the monitoring equipment

we installed at Bourton-on-the-Water at the meeting of 2 August. This

was installed following the BBC Country File programme in 2018, to

monitor the impacts of the Combined Sewer Overflow, (CSO) primarily in

response to concerns raised by WASP. We did inform Thames Water the

monitoring was taking place. The monitors (Sondes) were placed on the

River Windrush to measure upstream of the CSO outfall, as a control,

as well as downstream. I understand the reasons for the locations were

explained to WASP at a meeting in July 2018 and I understand a

demonstration was given at this meeting. Since then members of WASP

have been able to view the data live on a 24/7 basis. A third monitor

was placed for a short period of time at the confluence of the River

Dikler and the River Windrush to investigate any differences between

the two rivers.


The water quality monitors were in place for around a 10 month period

and there was no discernible difference between the water quality (for

those parameters we have tested against relevant to indicators for

sewage pollution) of the upstream monitoring point and the downstream

monitoring or in the monitoring at the confluence of the River Dikler

and the River Windrush.


Whilst there was no repeat of the sustained rainfall event and long

lasting combined sewer overflow of April 2018, during the monitoring

period, there were a number of significant rainfall events and

operations of the CSO but no impact was detected. We did not see any

evidence of discharges being made at times when there had not been

heavy rain. We would ideally like to measure impact on water quality

during a sustained event like that of April 2018 and subject to

resources, we would be willing to deploy water quality monitoring

equipment to better understand if larger more sustained discharges

impact water quality in the River Windrush. In addition to not

detecting an impact on water quality from the CSO the water quality

monitoring has also shown very good background water quality in the

River Windrush over the period of monitoring.


I understand your photographs and turbidity are consistent with the

monitoring results and observations by my officers. We will continue

to review our data and observations of the River Windrush. As you are

aware, there are discharges of storm sewage and treated effluent from

Water Company discharges alongside a range of other private discharges

into the River Windrush. There are also many other discharges to the

river as well as other factors that may have an impact such as diffuse

agricultural and urban pollution. We do not have the evidence at this

stage that the turbidity is caused by sewage or that the water quality

of the river is deteriorating.


I am concerned you have said that we are routinely issuing permits to

sewage works with illegal infrastructure. I would refute your

statement but if you have evidence to support your allegations then I

would be happy to receive the evidence. I have been made aware of a

specific issue at Bourton-on-the-Water sewage works and our officers

have required Thames Water to rectify it. We have taken a firm stance

on what is a complex regulatory issue. Spills are currently being

measured through event duration monitoring and we will continue to

assess the risk presented which we currently believe to be low.


Please continue to report any pollution incidents to us on

0800-80-70-60. We assess all reports and respond on a risk based

approach. If anyone causes a serious or significant pollution we will

take action.


You will be aware of the recent prosecutions, the most recent of which

was last month when Thames Water were ordered to pay fines and costs

of £707,000 at Aylesbury Crown Court for a pollution of the Maidenhead

Ditch which included an illegal storm discharge. The prosecutions we

took against Thames Water in 2017 resulted in a record fine and costs

in excess of £20 million. In 2018 we prosecuted for a discharge at

Milton-under-Wychwood which resulted in £1.8 million fine and costs

and a further £200,000 being voluntarily given by the Water Company to

three environmental charities who work in the local area. As a direct

result of the action we have taken in recent years Thames Water have

made a number of improvements and we hope one effect of the

prosecutions will be to push the environment higher up the Thames

Water agenda reducing the risk of pollution in much of the Thames

Area. My officers are taking strong and proportionate action where

Thames Water have caused significant pollution events.


We will continue to take action in line with our Enforcement and

Sanctions Policy. I understand you are aware of the report recently


In the accompanying press release we issued it said: “Environment

Agency Chair Emma Howard Boyd, who has previously warned water

companies they would face a tougher regulatory approach with

increasing inspections, is pledging that the Environment Agency will

continue to work with Ofwat to look at financial penalties to drive

better environmental performance given fines are currently only a

fraction of turnover. Writing in the report’s foreword she said:


“Companies should be reflecting on their environmental performance and

long-term resilience, if this is poor they should be asking themselves

whether dividends are justifiable.”


Lastly, we would like to reiterate our commitment to protecting the

environment which is something we care passionately about. Please rest

assured our local officers will continue to work tirelessly to protect

and improve the River Windrush and more widely the watercourses in the

Thames Area.


Yours sincerely


C Chiverton


Colin Chiverton


Acting Area Director


On behalf of Julia Simpson


Area Director – Thames


Environment Agency

©2019 Windrush Against Sewage Pollution