Chapel Porth is on the north coast of Cornwall, approximately three kilometres from
St Agnes. At high tide the beach is a small sand and shingle cove approximately 130
metres wide. At low tide a large stretch of sandy beach approximately one kilometre
wide is exposed between Tubby's Head and the neighbouring beach at Porthtowan. The
beach is backed by large moorland covered cliffs which are dotted with caves and several
natural arches.
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 54% 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.
Environment Agency samplers make observations of litter present on the beach at every
visit, this includes assessments of sewage debris, litter and tar. At Chapel Porth
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 4% of visits. Litter was not assessed as being sufficient to be objectionable,
but was observed as being present on 33% of visits. Tarry residue was not noted at
this site.
There are nine farms in the catchment, most of which are arable and dairy. During
and after periods of heavy rainfall, runoff to the streams from agricultural land
is greatly increased, and the quality of the bathing water can be reduced.
The catchment surrounding Chapel Porth is approximately 460 hectares. The Chapel Coombe
stream enters the sea at the bathing water. The steep catchment means rain runs off
rapidly into the streams.
The Chapel Porth catchment is an old mining valley with several disused tin and copper
mines including the Charlotte United Mines. There are small urban settlements at Goonvrea
and Mingoose along with several other properties dispersed around the catchment. Land
use is mainly agricultural, with approximately nine farms and several campsites. The
catchment is within a number of national and international designations including,
the Cornwall Area of Outstanding Natural Beauty (AONB), the Godrevy Head to St Agnes
Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC),
and the St Agnes Heritage Coast.
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.