When will it be safe to kayak or swim in the R. Dee in Chester?

John Lewis made this Freedom of Information request to Welsh Water
You only have a right in law to access information about the environment from this authority
This request has been closed to new correspondence. Contact us if you think it should be reopened.

The request was partially successful.

Dear Welsh Water,
I am aware that sewage is discharged into the River Dee. Information on releases appears to be shown only after a release.
I have three requests for information;

1. How many times in the last 12 months (April2020-April 2021) has sewage been released into the Dee?
2. Why cannot we be given advanced warnings and information when discharges are expected?
3. At what date in the future do you expect the water of the Dee between Eccleston and Chester to meet designated bathing water status?

Yours faithfully,

John Lewis,
Chair, Deva Canoe Club

Environmental Information Requests, Welsh Water

Dear Mr Lewis

 

Request for information

We refer to your request for information which was received on 31^st March
2021.

We are not a public authority for the purposes of the Freedom of
Information Act 2000. However, we are considering your request under our
obligation as a public authority for the purposes of the Environmental
Information Regulations 2004 (“the Regulations”).

In accordance with the Regulations, we will respond to your request within
20 working days of the date of receipt. If you have any queries in the
meantime, please do not hesitate to contact me.

In the meantime, if you have any queries, please contact us on email
[1][email address]

We have assigned reference EIR/738/2021 to your request. Please kindly
note this in all correspondence with us regarding this matter.

Yours sincerely,

R.Stevens

Dŵr Cymru Welsh Water

 

 

 

_______________________________________________________ Dwr Cymru Welsh
Water is firmly committed to water conservation and promoting water
efficiency. Please log on to our website www.dwrcymru.com/waterefficiency
to find out how you can become water wise. Mae Dwr Cymru Welsh Water wedi
ymrwymo i warchod adnoddau dwr a hyrwyddo defnydd dwr effeithiol. Mae
cyngor i' ch helpu i ddefnyddio dwr yn ddoeth yn
www.dwrcymru.com/waterefficiency

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Environmental Information Requests, Welsh Water

Our Reference: EIR/738/2021

 

 

Dear Mr Lewis

 

Request for information

We write further to your request for information dated 31^st March 2021,
which we have been considering under
the Environmental Information Regulations 2004.

 

I can confirm that Dwr Cymru Welsh Water does hold the information you
have requested.

We have set below your questions followed by our responses.

1. How many times in the last 12 months (April2020-April 2021) has sewage
been released into the Dee?

  01/04 - 31/12/2020 01/01 - 12/04/2021 Total
No of discharges   990 544 1524

 

We have assumed in our response that your request relates to discharges
from our CSO (Combined Sewer Overflow) assets as these operate on an
intermittent basis.

The overall number of discharges from 39 assets (CSOs) directly
discharging into river Dee in the period from 01/04/2020 to 12/04/2021 was
1524.

Please note, the above table includes discharges that occurred from
01/042020 to 12/04/2021. We have excluded assets discharging into
tributaries and into the estuary of the River Dee. There are 39 assets
monitored in event duration monitors (EDM) which discharge directly into
river Dee. The EDM spill data from these assets was used to provide the
final figures.

2. Why cannot we be given advanced warnings and information when
discharges are expected?

There are many factors that affect Sewerage network and WwTW discharges
and each discharge location and its relationship with the upstream
catchment is unique. Factors include: 

o Whether a sewerage network is combined (rainwater and sewage) or foul
only (sewage),
o The duration and intensity of any rainfall.
o The surrounding soil moisture level (degree of saturation).
o Topography of the catchment and the time of day (night-time has lower
water use resulting in greater space in the sewer).
o Rainfall events which occur immediately after a previous event will
also have a greater impact due to the sewer Network not having
sufficient time to recover from previous rainfall.

We do operate predicative spill software that monitors our CSO’s
performance and detects abnormal operation in dry weather, allowing us to
schedule a Wastewater operations crew to attend and take action to prevent
a pollution. Unfortunately, this system does not work reliably during
rainfall. As the majority of our discharges are as a result of rainfall,
and the response time of our network to heavy rainfall is usually quite
short,  any predictive alert would, in all likelihood, be of very short
precedence to an actual spill event.

We are currently trialling a number of predictive computer algorithms that
may be able to use our current telemetry data, linked to live rainfall
information, to provide a more advanced estimate of a spill occurring.
However, these are still in the very early stages of development and not
yet sufficiently reliable to be able to confidently provide public alerts.
It is unlikely this will develop to a useable system within the next
couple of years.

Although we have an extensive monitoring system on our sewer network, this
system is not set up  set up to disseminate ‘near real time’ spill event
data from all our assets..  However we do operate a ‘near live’ spill
alarm service for the Dee (a 5km reach between Eccleston and the tidal
weir near the Groves in Chester) which feeds into the Safer Seas Service
provided by Surfers Against Sewage (SAS) which can be found on the
following link [1]https://www.sas.org.uk/map/. This is an interactive map
which will alert you to any discharge from a CSO in the previous 48 hours.

 

3. At what date in the future do you expect the water of the Dee between
Eccleston and Chester to meet designated bathing water status?

At present the river Dee between Eccleston and Chester is not designated
as a bathing water and we have no planned investment in the area
associated with bathing water quality improvements. Any new designation is
for government to decide; this will be Defra in England and Welsh
Government in Wales.  You should be aware that water quality will be
affected by both point source discharges and diffuse sources that include
treated wastewater from Sewage works, private sewage discharges, urban
drainage agricultural run-off and rainwater mixed with wastewater from CSO
discharges. Therefore, once a new designation has been agreed, it is up to
the Environmental Regulator (Environment Agency in England and Natural
Resources Wales in Wales) to plan how improvements to water quality to the
required bacteriological standard will be achieved.   

We hope that this response is clear. Should you have any questions, please
contact us by email at [2][email address].

If you are dissatisfied with the handling of your request, you have the
right to ask for an internal review. Internal review requests should be
submitted within 40 working days of the date of receipt of this response
and should be addressed to Company Secretary, Linea, Fortran Road, St
Mellons, Cardiff CF3 0LT

If you are not content with the outcome of the internal review, you have
the right to apply directly to the Information Commissioner for a
decision.

 

Yours sincerely,

R.Stevens

Dŵr Cymru Welsh Water

 

_______________________________________________________ Dwr Cymru Welsh
Water is firmly committed to water conservation and promoting water
efficiency. Please log on to our website www.dwrcymru.com/waterefficiency
to find out how you can become water wise. Mae Dwr Cymru Welsh Water wedi
ymrwymo i warchod adnoddau dwr a hyrwyddo defnydd dwr effeithiol. Mae
cyngor i' ch helpu i ddefnyddio dwr yn ddoeth yn
www.dwrcymru.com/waterefficiency

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