Shanklin beach on the south east coast of the Isle of Wight is towards the south of
Sandown Bay. The southern half of the sandy beach slopes gently up to the cliffs with
a rock ledge at its extremity and the northern half is backed by the resort's esplanade.
The beach is popular with anglers.. A stream flows to the beach from Shanklin Chine.
This bathing water could be affected by discharges from the Hope Beach storm overflow
to the north of the beach that occur when heavy rainfall overwhelms the sewerage system.
Since 2018 Southern Water completed upgrades to a pumping station, which will reduce
discharges from the storm overflow.
Sandown sewage treatment works long sea outfall was commissioned in 2001 and flows
diverted to it from short outfalls at Bembridge and Sandown. Further treatment was
installed at Sandown sewage treatment works prior to 2003.
As part of Southern Water’s Bathing Water Enhancement Programme (from 2016 to 2019),
Southern Water have worked with partners and delivered solutions to improve bathing
water quality.
Effluent from the short Sandown outfall used to impact this bathing water. Water quality
drastically improved around 2001 when the Sandown sewage treatment works long sea
outfall was commissioned and flows were diverted from the Bembridge and Sandown short
outfalls. A routine sample failed mandatory standards in June 2010 and follow-up investigations
by the Environment Agency, the local authority and the water company discovered a
blocked sewer overflowing into a highway drain and then reaching the beach along the
Shanklin Chine stream. After the sewer was repaired monitoring of the bathing water
showed that water quality had improved. Additional sampling from the Chine was undertaken
in 2015 to increase our knowledge and to try and identify possible sources of contamination.
If any concerns arise, we will investigate and request immediate remedial action from
those responsible.
For the four year (2020-2023) assessment period where data is available, seaweed (macroalgae)
was assessed as being sufficient to be objectionable for 2% of visits, with 67% of
visits noting the presence of seaweed (macroalgae). The shore can become covered with
seaweed, depending on tides and the weather. Groynes, rocks and other fixed objects
may have a covering of seaweed which can be slippery.
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.
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 5% of visits. Microscopic algae (phytoplankton) increase
in number at certain times of the year. This process is known as a phytoplankton bloom.
Blooms of phytoplankton can result in the water appearing discoloured or a foam forming
on the water.
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.
The Environment Agency makes a daily pollution risk forecast at this site based on
the effects of rain, tide 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 cause a temporary reduction in water quality, we will
issue a pollution risk warning on this website. Water quality will 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 11 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.
A stream flows to the beach from Shanklin Chine. Within the stream's catchment there
are storm water outfalls which after periods of heavy rainfall could have an adverse
affect on bathing water quality.
The Sandown sewage treatment works long sea outfall, about 4.2 km to the east of this
bathing water, is designed to ensure that the bathing water is protected.
Environment Agency samplers make observations of litter present on the beach at every
visit, this includes assessments of sewage debris, litter and tar. At Shanklin 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 35% of visits. Tarry residue was not noted at
this site.
The natural drainage (hydrological) catchment surrounding the bathing water is about
200 hectares. The southern part of the catchment includes rural downland and the northern
part much of the town of Shanklin.
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.
