Portwrinkle is on the south coast of Cornwall. It is a remote sand and rock beach,
approximately one kilometre wide, backed by cliffs. There are lots of rock pools to
explore at low tide.
There is an emergency/storm overflow from the Portwrinkle STW, that discharges into
the sea 300m southeast of the Environment Agency monitoring point. The operation of
the overflow can lead to a temporary drop in bathing water quality.
This bathing water is included in the Surfers Against Sewage “Safer Seas Service”.
This service can alert you to Combined Storm Sewer Overflow discharges via a phone
App and in addition, it includes the Environment Agency Pollution Risk Forecast warnings
where they are available. Further details of the service can be found at - http://www.sas.org.uk/safer-seas-service/
The South West Water sewage treatment scheme for Portwrinkle, which provides secondary
treatment and discharges through an extended outfall, was completed in 1995. Storm
overflow event duration monitoring (EDM) was installed at Portwrinkle Tank combined
sewer overflow by May 2011.
For the three year (2021-2023) assessment period where data is available, seaweed
(macroalgae) was assessed as being sufficient to be objectionable for 4% of visits,
with 92% of visits noting the presence of seaweed (macroalgae). This bathing water
does not have a history of large amounts of seaweed (macro algae).
For the three year (2021-2023) assessment period where data is available, phytoplankton
(microscopic algae) was not noted at this site. Phytoplankton (microscopic algae)
naturally increase in number at certain times of the year. This process is known as
a phytoplankton bloom. This bathing water does not have a 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.
There are no active pollution risk forecasts made at this bathing water. However any
bathing water has the potential to be affected by a pollution incident and if this
occurs a pollution risk warning with associated advice against bathing will be issued
on this website.
The outfall from the Portwrinkle STW discharges to the sea 350 metres (m) southwest
of the Environment Agency monitoring point. This discharge is 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 Portwrinkle
for the three year (2021-2023) assessment period where data is available, sewage debris
was not noted at this site. Litter was not assessed as being sufficient to be objectionable,
but was observed as being present on 32% of visits. Tarry residue was not assessed
as being sufficient to be objectionable, but was observed as being present on 4% of
visits.
The catchment surrounding Portwrinkle is approximately 24 hectares. There are no streams
within the beach area. The small urban area of Portwrinkle is set back behind the
cliffs that surround the beach.
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.
