Porth Beach is on the north coast of Cornwall. It is a rural sandy beach, approximately
230 metres wide, surrounded by cliffs with a stream flowing the across the beach to
the sea.
There is an emergency/storm overflow from the Porth pumping station, that discharges
to the Porth Stream 100m from the beach. The operation of the overflow can lead to
a temporary drop in water quality in the Porth Stream and Porth bathing water.
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 sewage treatment scheme for Newquay, which provides secondary treatment and ultraviolet
disinfection, was completed by South West Water in April 2000. Extensive sewerage
work to combined sewer overflows in the Newquay area was also carried out at that
time. Storm overflow event duration monitoring (EDM) was installed at the Porth pumping
station by December 2011.
The Environment Agency have carried out extensive additional catchment monitoring
alongside the Environment Agency routine bathing water monitoring. The Environment
Agency have used a DNA tracing technique to help us identify whether sources of faecal
pollution are human or animal. This has indicated a mixture of human and animal faeces
in the catchment. The reduced salinities of bathing water samples and salinity surveys
demonstrate a strong freshwater influence from the Porth Stream on the bathing water
sample point. Reduced water quality at the bathing water sampling point can occur
during heavy rain and certain states of the tide. The Environment Agency have completed
catchment walkovers and used continuous water quality monitors to identify sources
of pollution to the Porth Stream catchment. The use of continuous water quality monitors
will be ongoing during the 2019 bathing season.
Environment Agency and South West Water misconnection investigations are ongoing within
Porth. No issues have been identified so far.
The Environment Agency have regularly inspected and sampled surface water outfalls
and are working with the local authority to reduce the impact of drainage from urban
areas.
After discussions with the Environment Agency, Cornwall Council agreed that all gully
pot clearing would occur outside of the bathing season to minimise the risk of pollution
to the bathing water at Porth.
In partnership with the Environment Agency, Surfer's Against Sewage launched their
Cleaner Coastal Catchments initiative in this catchment in 2015. The initiative focused
on community engagement and encouraging the public to pledge to take a number of actions
that will contribute to improving water quality at Porth.
Cornwall Wildlife Trust, on behalf of the Environment Agency, ran a Yellow Fish and
FOG (Fats, Oil and Grease) campaign during the 2018 season to raise awareness of sources
of water pollution. The campaign highlighted the damage caused by pouring oils, paints,
solvents, chemicals or dirty water down highway gullies or surface drains.
For the four year (2020-2023) assessment period where data is available, seaweed (macroalgae)
was not assessed as being sufficient to be objectionable, but was observed as being
present on 94% of visits. This bathing water does not have a history of large amounts
of seaweed (macro algae).
Wrongly connected domestic waste water pipes can also affect the bathing water quality.
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 1% 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, however,
the Porth Reservoir upstream of the bathing water does have a history of algal 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.
This bathing water is subject to short term pollution procedures. The Environment
Agency makes a daily pollution risk forecast at this site based on the effects of
rain, tide, wind, sunlight 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 make short term pollution likely we issue a pollution
risk warning on this website and the beach manager will display a sign advising against
bathing at the bathing water. After a short term pollution event, levels of bacteria
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 19 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.
Streams and rivers are typically affected by human sewage, animal slurry and runoff
from roads. The Porth Stream flows across this beach. The Environment Agency have
monitored the stream since 1990 and found that water quality is temporarily worse
during and after heavy rainfall.
Due to drought conditions, in January 2023 SWW were granted an abstraction licence
for Porth reservoir. This will reduce the flow from the reservoir into the Porth stream
but as part of the permit a set flow must be maintained to preserve fish spawn and
inhabiting wildlife. This change in flow may have an effect on the bathing water quality
so the Environment Agency will be continuing to sample and monitor any impacts.
The outfall for the Newquay STW discharges into the sea approximately 2.9km west of
Porth bathing water at Towan Head. 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 Porth for the
four year (2020-2023) assessment period where data is available, sewage debris was
not noted at this site. Litter was assessed as being sufficient to be objectionable
for 3% of visits, with 66% of visits noting the presence of litter. Tarry residue
was not noted at this site.
There are approximately 20 farms in the catchment, including sheep, cattle and arable.
During and after periods of heavy rainfall, runoff to the Porth Stream from agricultural
land is greatly increased, and the quality of the bathing water can be reduced. The
Environment Agency are working with the farming community to reduce the runoff in
areas of greatest risk.
In 2015,the Environment Agency funded fencing materials for two farms in the lower
catchment to prevent cattle access to streams. Catchment Sensitive Farming are also
working in catchment to provide advice and guidance on available grants.
There are two private sewage treatment works with discharge consents to the Whipsiderry
Stream tributary of the Porth Stream. There are also a number of minor private sewage
treatment systems with discharge consents serving holiday parks and private dwellings
throughout the catchment. The Environment Agency are working with the owners to protect
water quality and continue to monitor compliance with consent conditions.
The catchment surrounding Porth is approximately 3,650 hectares. The Porth Stream
is approximately 12 kilometres (km) (24 km long including major tributaries) and rises
near Ruthvoes in the east of the catchment close to the A30. The stream feeds the
Porth Reservoir eight kilometres inland then flows to the coast at Porth where it
enters the sea at the northern end of the beach.
The steep catchment means rain runs off rapidly into the stream especially towards
the coast. Land use is mostly agricultural, with around 20 farms. The rural areas
are a patchwork of improved grassland, arable and mixed woodland. The urban areas
include parts of Newquay, St Columb Major and Indian Queens and there are caravan
sites within the catchment.
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.