The bathing water is located in a long curved north facing bay. The beach is a gently sloping sandy beach as is backed by boulder clay cliffs. The beach is backed by the town of Nefyn, and then agricultural land. The cliffs are part of the Porth Dinllaen to Porth Pistyll SSSI and also the Clogwyni Pen Llyn / Seacliffs of Llyn Special Area of Conservation. The water quality sample point lies opposite the end of the minor road down onto the beach.
Investigations are undertaken during the season when necessary, such as occasions where elevated bacterial results in the bathing water cannot be simply explained as due to weather conditions.
Nefyn Pumping Station is the nearest storm and emergency overflow to the bathing water monitoring point. This discharge point is located approximately 1.1km to the north east of the sampling point.
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. There are no known misconnections in the Nefyn area.
Phytoplankton (microscopic algae) naturally increase in number at certain times of the year. This process is known as a phytoplankton bloom.
Algal Blooms can occur at any beach during the bathing season and are usually noticeable by a surface scum. This beach has no history of such blooms.
There are a number of small springs which discharge from the base of the cliffs across the beach and a tiny stream near the beach café. Otherwise the nearest watercourse that discharges onto the beach is around 1.1km to the north east of the sampling point.
Sewage from Nefyn and Morfa Nefyn is pumped to a Dwr Cymru sewage treatment plant located between Morfa Nefyn and the village of Edern. The treated effluent from this membrane treatment plant discharges to the Afon Geirch near Edern. This river discharges out to sea to the west of Porth Dinllaen headland and is over 5km from the monitoring point for this beach.
Natural Resources Wales samplers make visual observations of the beach at every visit, this includes assessments of sewage debris, animal faeces, litter and oil or tar. As a newly designated beach data is not yet available for Porth Nefyn, following the 2024 season noted observations will be analysed and reported.
Apart from the stream that’s a kilometre to the north east of the sampling point, the land behind the beach drains to the Afon Geirch which flows away from the beach, so there should not be any agricultural impact on the bathing water. Agriculture in the area is a mix of sheep, beef and dairy farms.
The natural drainage catchment area surrounding the bathing water is largely rural, with the exception of the village of Nefyn and neighbouring Morfa Nefyn.
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 Wales 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 Natural Resources Wales' role to drive improvement of water quality at bathing waters that are at risk of failing European 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. The following sections serve to highlight potential sources of pollution, conditions under which they may arise and measures being put in place to improve water quality.
