Perranporth Penhale Sands is in the centre of Perran Sands on the north coast of Cornwall.
It is a sandy beach resort approximately one kilometre wide, backed by sand dunes.
A stream flows across the beach to the sea.
In the past the water quality at Perranporth was affected by an untreated sewage outfall
near Cligga Head and unsatisfactory combined sewer overflows (CSO) discharging to
the Bolingey Stream. A sewage treatment works (STW) for Perranporth was built at Cligga
Head by South West Water in late 1997. The scheme included a new relocated outfall,
resewerage and improvements to CSOs.
The outfall from the STW was relocated again in April 2005 and treatment was upgraded
to full secondary treatment and ultraviolet (UV) disinfection. Storm overflow event
duration monitoring (EDM) was installed at the Perranuthnoe pumping station by April
2011.
For the four year (2020-2023) assessment period where data is available, seaweed (macroalgae)
was assessed as being sufficient to be objectionable for 4% of visits, with 75% 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 four year (2020-2023) 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 Perranporth STW discharges to the sea approximately 2.3km southwest
of 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 Perranporth
Penhale Sands for the four year (2020-2023) 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 50% of visits. Tarry residue
was not noted at this site.
The catchment surrounding Perranporth Penhale Sands is approximately 3,650 hectares.
There are no streams entering the sea at the bathing water, however, the Bolingey
and Perrancoombe streams enter the sea one kilometre south at Perranporth. The Perrancoombe
Stream is approximately 7.6 kilometres (km) long and rises just north of the A30 flowing
northwards to Perranporth. The Bolingey Stream is approximately 16km long (including
tributaries). The steep catchment means rain runs off rapidly into the streams.
The catchment is mostly agricultural, with around 20 farms, and the rural areas are
mostly improved grassland, with some arable and wooded valleys, particularly on the
Bolingey Stream. Urban areas include Perranporth and Goonhavern and there are many
holiday camps and caravan sites in the catchment. Much of the coastline is designated
as a Site of Special Scientific Interest (SSSI) or Special Area of Conservation (SAC).
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.
