Sidmouth Town is on the south coast of Devon. It is a pebble beach, approximately
900 metres wide, with rock groynes backed by the promenade and town. The Sidmouth
area extends for five kilometres inland to include Sidford and Sidbury.
There are two emergency/storm overflows from the Ham pumping station, the first of
which discharges to the sea 620m from the beach. The second discharges to the River
Sid at Alma Bridge 380m from the Environment Agency monitoring point. The operation
of the overflows can lead to a temporary drop in bathing water quality.
The South West Water sewage treatment scheme for Sidmouth, which provides secondary
treatment and ultraviolet (UV) disinfection, was completed in 2001. Improvements were
made to the combined sewer overflow (CSO) to the Bickwell Brook in 2002. Storm overflow
event duration monitoring (EDM) was installed at Sidmouth STW (the Ham) pumping station
by May 2011.
In 2016 the Environment Agency carried out stream investigations to identify sources
of contamination to the stream. In 2015 the Environment Agency carried out a survey
to look at the suitability of the bathing water monitoring point. As a result of
this study, the monitoring point was relocated for the 2016 bathing season.
For the four year (2020-2023) assessment period where data is available, seaweed (macroalgae)
was not assessed as being sufficient to be objectionable, but was observed as being
present on 56% of visits. This bathing water does not have a history of large amounts
of seaweed (macro algae).
Modern sewerage systems have two separate systems, one takes foul sewage to sewage
treatment, the other takes rainwater runoff through surface water drains to rivers,
lakes and the sea. Misconnections occur when waste water pipes are plumbed into surface
water drains instead of the foul water sewerage system. This can give rise to pollution
when the waste water is discharged directly to the environment through the surface
water drain. For example, a washing machine or toilet may be incorrectly plumbed so
that it discharges to the surface drain rather than the foul sewage drain.
Wrongly connected domestic waste water pipes can also affect the bathing water quality.
An investigation in 2016 found a number of misconnections into the streams and a build-up
of fat in the foul sewer. These have now been rectified. We will continue to work
with East Devon District Council and South West Water to identify and rectify any
problems if they arise.
For the four year (2020-2023) assessment period where data is available, phytoplankton
(microscopic algae) was not assessed as being sufficient to be objectionable, but
was observed as being present on 6% of visits. Phytoplankton (microscopic algae) naturally
increase in number at certain times of the year. This process is known as a phytoplankton
bloom. These blooms can discolour the water or form as a foam on the water. This bathing
water has some history of phytoplankton blooms.
The risks to human health from contact, ingestion or inhalation with marine algae
that currently occur in UK coastal waters are considered to be low. However, some
individuals may be more sensitive and display some reactions.
A common marine algae found in UK coastal waters is Phaeocystis, which is often mistaken
for sewage as it forms foam and a brown scum, but it is non-toxic.
This bathing water is subject to short term pollution procedures. The Environment
Agency makes a daily pollution risk forecast at this site based on the effects of
rain, wind, sunlight and seasonality on bathing water quality. These factors affect
the levels of bacteria that get washed into the sea from livestock, sewage and urban
drainage via rivers and streams and how they disperse.
When these factors combine to make short term pollution likely we issue a pollution
risk warning on this website and the beach manager will display a sign advising against
bathing at the bathing water. After a short term pollution event, levels of bacteria
typically return to normal after a day or so but it’s possible to have several warning
days in a row. Details of the work to reduce the sources of bacteria at this bathing
water are detailed in this profile.
In 2023 3 pollution risk warnings were issued for this bathing water.
All bathing waters have the potential to be affected by a pollution incident and if
this occurs a pollution risk warning will be issued with associated advice against
bathing on this website.
Streams and rivers are typically affected by human sewage, animal slurry and runoff
from roads. The River Sid enters the sea to the east of the beach. The Environment
Agency have monitored the River Sid between 1995 and 2010, and found that water quality
is temporarily worse after heavy rainfall. The Bickwell Brook enters the sea 280m
west of the Environment Agency monitoring point. The Cotmaton Stream, which is largely
culverted and discharges 80m from the bathing water sampling point has been sampled
since 2016.
The Sidmouth STW outfall discharges to the sea 620m from the bathing water. This discharge
is disinfected and designed to protect bathing water quality.
Environment Agency samplers make observations of litter present on the beach at every
visit, this includes assessments of sewage debris, litter and tar. At Sidmouth Town
for the four year (2020-2023) assessment period where data is available, sewage debris
was not assessed as being sufficient to be objectionable, but was observed as being
present on 2% of visits. Litter was not assessed as being sufficient to be objectionable,
but was observed as being present on 49% of visits. Tarry residue was not noted at
this site.
There are farms in the catchment, which are dairy, beef, and arable. During and after
periods of heavy rainfall, runoff from agricultural land is greatly increased, and
the quality of the bathing water can be reduced. The Environment Agency continue to
work with farmers to improve their environmental performance.
The Environment Agency have worked with businesses on the Alexandria Industrial Estate
and Manstone Avenue Industrial Estate to ensure there is no effect on the bathing
water quality from these sites. A pollution campaign at both sites has resulted in
an improvement in water quality.
The catchment surrounding Sidmouth is approximately 4200 hectares. The River Sid rises
on the edge of Pen Hill Woods above Ottery St Mary and flows south through Sidbury
to the sea at Sidmouth 330m east of the Environment Agency monitoring point. The steep
catchment means rain runs off rapidly into the River Sid and onto the beach. The Bickwell
Brook is approximately 2.3 kilometres long and flows through the western part of Sidmouth
to the sea 280m west of the Environment Agency monitoring point. The catchment close
to the beach is urban, and in the wider catchment it is mostly agriculture and forestry.
Seaweed (macroalgae) and phytoplankton (microscopic algae) are a natural part of the
marine and freshwater environment. Below we note whether these have been recorded
in quantities sufficient to be a nuisance.
The majority of sewers in England are “combined sewers” and carry both sewage and
surface water from roofs and drains. A storm overflow operates during heavy rainfall
when the sewerage system becomes overwhelmed by the amount of surface water. The overflow
prevents sewage from backing up pipes and flooding properties and gardens. An emergency
overflow will only operate infrequently, for example due to pump failure or blockage
in the sewerage system.
Heavy rain falling on pavements and roads often flows into surface water drains or
highway drains, ending up in local rivers and ultimately the sea. The quality of bathing
water may be adversely affected as a result of such events.
It is the Environment Agency role to drive improvement of water quality at bathing
waters that are at risk of failing higher standards. It is natural for water to run
off the land to the sea. Water quality at a bathing water is dependent upon the type
and area of land (the catchment) draining to the water and the activities undertaken
in that catchment.