Dear Mr Stockwell,
Thank you for your request for information, which we are dealing with under the requirements of the Environmental Information Regulations 2004.

We are proceeding with your application, which we received on the 3rd September.

It is our intention to have the information made available to you within 20 working days after receiving your request. If the request proves unduly complicated or the volume of information involved makes it impractical to comply with the request within the 20 working day period we will let you know and provide the information within 40 working days of receiving your request. There are a limited number of exemptions that may prevent us from releasing the information but we will try to answer your request in as much detail as possible.

If you have any questions or queries about your request, please do not hesitate to contact me, either via [Wessex Water request email] or on the details below.

Kindest regards,
Dave

Dave Jones
Senior Regulatory Scientist
Wessex Water
Claverton Down Bath BA2 7WW
Telephone 01225 52 6000
[email address]

show quoted sections

Dear Mr Stockwell,

Thank you for your email of the 3^rd September, in which you requested:

o How many storm overflow spill events occurred under the management of
Wessex Water between 01/01/21 and 31/08/21?
o What duration (hrs) of storm overflow spill events occurred under the
management of Wessex Water between 01/01/21 and 31/08/21?
o Please provide information about the number and size of fines Wessex
Water Services Limited received from the Environment Agency over the
last decade, due to sewage spills into rivers.

Wessex Water operates a total of 1,286 Storm Overflows and of these, Event
Duration Monitoring (EDM) data is readily available for 1,005 (78%). The
remaining EDM installations are due for completion over the next 18 months
(22%).  

Using the readily available data:

o There were 14,257 discharge events from Storm Overflows during the
period 01/01/2021 and 31/08/2021.  This is based upon the Environment
Agency’s 12/24 counting methodology. This basically equates to 'number
of 24 hr periods that saw some discharge activity from an individual
overflow'.
o  The duration of storm overflow operation was 107,731 hours for the
above period.  This equates to an average of 7.6 hours per discharge,
with an average of 14.2 discharges per overflow (12/24 counting).

Please note that we will be reporting this data formally to the
Environment Agency for the whole of 2021 at the end of February, and
making the data available on our web site.  Prior to that, spill counts
and durations for some overflows may change during our quality assurance
processing.  We believe the data presented here to be a fair reflection of
our storm overflow performance, however.

With regard to your question on the number and size of fines, the attached
spreadsheet provides a summary of the enforcement action taken against us
by the Environment Agency over the last decade which resulted in fines or
other payments.  Please note:

o During the period, the Government introduced the Civil Sanctions
regime under the Regulatory Enforcement and Civil Sanctions Act 2008. 
This provides the Environment Agency with a range of enforcement
options without going to Court.  These sanctions can include Variable
or Fixed Monetary Penalties, Compliance/Restoration/Stop Notices or
Enforcement Undertakings (EU).  EU’s are a voluntary offer by an
offender to put right the effects of their offending, the impact on
third parties and to make sure it cannot happen again.
o Following several unfortunate pollution incidents caused by our assets
over the last decade, we have offered several Enforcement Undertakings
to the Environment Agency.  I have therefore also included figures
relevant to these within the list of enforcement action.

What are Storm Overflows and why are they needed?

The reason storm overflows exist is because many sewers were laid at a
time when drains carried both rainwater and sewage. They should only
operate during periods of intense rainfall, where they act as relief
valves to allow excess stormwater to be released to rivers or the sea.
This protects properties from flooding and prevents sewage backing up into
streets and homes during heavy storm events. Storm overflows operate under
permits from the Environment Agency, who have published a blog about their
role, which you can find [1]here.  Storm overflows are designed in such a
way as to avoid adverse environmental impact on the receiving waters.
Indeed, [2]national and publicly available data shows that only around 4%
of the reasons waterbodies do not meet environmental standards are due to
the operation of storm overflows.

Under storm conditions, any foul water released from a storm overflow is
heavily diluted by large volumes of rainwater. Flows are further diluted
by the watercourse as this will also be swollen by the same heavy rain.
Many storm overflows are fitted with screens to prevent debris entering
the watercourse, or have attenuation tanks which also improve water
quality. We currently monitor around 78% of storm overflows through Event
Duration Monitoring (EDM) and have a programme in place to install
monitoring equipment on all by 2023, ahead of the regulatory requirement
of 2025. Pollution incidents are rarely caused by a storm overflow which
has operated correctly, as there is no significant environmental impact in
terms of ammonia, suspended solids and biochemical oxygen demand. The
standards we work to are designed to protect the environment and to ensure
the benefits of a diverse environment.

We have also provided further background information on Storm Overflows on
our website:

o Our Storm Overflow page
([3]https://www.wessexwater.co.uk/services/s...)
includes a more detailed overview of the issue, (which is also
attached to this email).
o Information on the location and frequency of operation of Wessex Water
Storm Overflows, and their EDM status, can be found on our Drainage
and Wastewater Management Plan Portal
-[4]https://wessexwater.maps.arcgis.com/apps...
Please look at the ‘Performance’ tab under the ‘Storm Overflows’
section as this links to a spreadsheet detailing the performance of
all of our overflows fitted with Event Duration Monitoring (EDM),
including all stop/start times for individual sites for 2020.  The
Read Me tab explains more about this data.
o Our Wild Swimming page
([5]https://www.wessexwater.co.uk/environmen...)
provides information and linkages to external advice on this topic. 

What are we doing to improve Storm Overflows

We support the ambition to reduce impacts from our overflows and in an
ideal world, we would not have combined sewerage systems.  We fully
recognise that climate change is resulting in more intense rainfall
events, and the amount of surface water being connected by households (for
instance by paving over driveways so cars can be charged overnight),
continually adds to the amount of surface water being added to the
combined sewerage network.

Some of our overflows also suffer from groundwater infiltration into our
sewers.  In wet weather the ground water table can become very high, and
this water can enter into and inundate our (public) and others’ (private)
sewers. We have produced a video explaining this phenomenon and what can
be done. The video is available to view on YouTube and can be opened by
clicking  [6]here.  Some sewers in rural villages can be significantly
affected by groundwater inundation because the sewers are designed to
accommodate foul only flows, so are typically only 150 mm in diameter.
Whilst sewerage undertakers have powers to inspect private drains, it is
worth noting that powers that require owners to rectify private leaking
drains (the length of which exceeds the length of public sewers) do not
exist. Currently only Local Authorities have powers to require owners of
buildings to carry out remedial works on drains which are defective and
let sub-soil water in (Section 59 of the Public Health Act). Local
Authorities also have powers to repair private drains which are not
sufficiently maintained and recover costs (up to £250) from the owner
(Section 17 of the Public Health Act).  We are calling on Defra to provide
better legislation to support tackling this issue (as indicated in our
attached briefing note).  We have an Infiltration reduction programme
which aims to address such sites through works such as sewer sealing,
which is reported on our website ([7]here).

The Government has established a [8]storm overflows taskforce, of which we
are a member, to consider how best to ensure that overflows do not cause
harm.  Eliminating storm overflows across England and Wales would cost
between £300bn and £500bn, so the immediate focus is to identify those
overflows that will potentially cause environmental or public health harm,
addressing those and then progressively working through the others.  Since
2000, we have invested £181m to upgrade over 500 overflows and a further
£150m is being invested in the current period 2020-25.

Addressing storm overflows is a complex issue which will take many years
to improve and will require Government to lead on changes to existing
legislation, run in parallel with a step-change in investment in surface
water separation (and greater combined sewage attenuation only where
separation is not feasible) plus changes in societal flushing habits. More
information can be found on our briefing note [9]here and which is
attached to this email. 

We are proactively using the data from Event Duration Monitoring (EDM) to
determine where storm overflows are not operating as we would expect and
investigating them through the [10]Storm Overflow Assessment Framework.
This provides a framework in which to identify storm overflows which
discharge frequently and address the issues they cause through
improvements.  We are also tackling misconnections from customers
properties to our networks and educating our customers on how to avoid
sewer blockages that cause pollutions.

As part of our Business Plan for 2020-2025, the Environment Agency has
included 13 storm overflow improvements as part of the Water Industry
National Environment Programme (WINEP). In addition, we have agreed a
bespoke Performance Commitment for this period which will provide a
mechanism for us to deliver more storm overflow improvements than the
schemes included in the WINEP. Our aim over this period is to further
reduce the number of SOs that frequently discharge into rivers and the sea
beyond the 13 included on the WINEP.   Plans for tackling overflows will
in the future be documented in our Drainage and Wastewater Management
Plans – please see our plans
at [11]https://www.wessexwater.co.uk/environmen...
 

I have also attached a copy of our Bristol Avon Factsheet, which sets out
the key issues within the Bristol Avon catchment, what we have done to
date to tackle them and our investment plans up to 2025.  We are also
working with several groups who are actively seeking to designate sections
of the River Avon as a bathing water.  For example at Warleigh Weir (near
Bath), we are undertaking a more extensive investigation into water
quality affecting the site which will cover more than one year and use the
outcome of these surveys to determine investment requirements within the
catchment to support any application to designate the site as an inland
bathing water.  Further information is available on our website at
 [12]https://www.wessexwater.co.uk/warleigh-w... In addition, we are
also supporting the Conham Bathing Water group in Bristol, alongside our
work with Bristol City Council in the Floating Harbour.  Please do bear in
mind that as well as contributions from our storm overflows, water quality
in the river that can affect public health can be influenced from other
activities such as agricultural practices, septic tanks and road drainage.

If I can be of any further assistance, or if you have any questions or
queries, please do not hesitate to contact me, either via
[13][Wessex Water request email] or at the address below.

We have dealt with your request for information under the requirements of
the Environmental Information Regulations 2004. If you are dissatisfied
with the handling of your request for environmental information, you may
request an internal review. Internal review requests should be submitted
within 40 working days of the date of this response and should be
addressed to [14][Wessex Water request email].   

If you are dissatisfied with the outcome of the internal review, you may
apply without charge to the Information Commissioner, who will consider
whether we have complied with our obligations under the Environmental
Information Regulations and who will require us to remedy any problems.
You can find out more about how to do this and about the EIRs in general
on the Information Commissioner’s website at [15]www.ico.org.uk.
 Complaints to the Information Commissioner may be made via the “report a
concern” section of the Information Commissioner’s website.

Kindest regards,
Dave

Dave Jones
Senior Regulatory Scientist
Wessex Water
Claverton Down Bath BA2 7WW
Telephone 01225 52 6000
[16][email address] [17]wessexwater.co.uk

show quoted sections