Constantine Bay is on the north coast of Cornwall. It is a rural sandy beach, approximately
660 metres wide, backed by sand dunes and edge by rocky outcrops. There are several
rock pools exposed at low tide.
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 68% of
visits noting the presence of seaweed (macroalgae). The bathing water can become covered
with large amounts of seaweed, depending on tides and the weather. This bathing water
does not have a history of large amounts of seaweed, although it can be noticeable
at times.
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 4% of visits. 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.
Streams and rivers are typically affected by human sewage, animal slurry and runoff
from roads. There is a very small stream flowing onto this beach which can affect
water quality after heavy rainfall.
Environment Agency samplers make observations of litter present on the beach at every
visit, this includes assessments of sewage debris, litter and tar. At Constantine
Bay 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 36% of visits. Tarry residue
was not noted at this site.
The catchment surrounding Constantine Bay is approximately 250 hectares. The stream
that enters the sea at the beach is approximately two and a half kilometres (km) long.
It flows through the small rural settlement of Constantine Bay before disappearing
into the sand at the beach. This is not a very steep catchment and there is an area
of flat dunes behind the bay which includes a golf course. This area and much of the
lower part of the catchment is designated as Trevose Head and Constantine Bay Site
of Special Scientific Interest (SSSI). The catchment is within the Cornwall Area of
Outstanding Natural Beauty (AONB).
Land use is split between improved grassland and arable, and also includes the urban
areas of Constantine Bay and St Merryn.
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.