The beach is gently sloping and made up of sand and pebble. On a low tide, ancient peat beds are exposed on the west side of the bay, near to the boat lane. The beach is backed by the village of Port Eynon, with a car park in the immediate vicinity and sand dunes stretching east to Horton. The headlands form part of a Site of Special Scientific Interest, whilst the bay area makes up part of the Carmarthenshire Estuary Special Area of Conservation. The designated sample point is located opposite the roundabout, at the western end of the Bay.
Natural Resources Wales works to establish sources of pollution around Port Eynon. Some of this work is carried out in partnership with Swansea Council and Dŵr Cymru Welsh Water.
Inspections are carried out by Natural Resources Wales in partnership with the local authority and the water company. These are carried out pre-season (before the 15th of May) and mid-season, if required (during the bathing water season).
Overton Sewage Treatment Works has a storm overflow. This protects domestic properties in the area from being flooded by sewage during periods of heavy rainfall.
A project known as Event Duration Monitoring (EDM) is underway to install telemetry on Combined Sewer Overflows (CSOs) by 2020 so that Dŵr Cymru Welsh Water (DCWW) know when the CSOs are operating and can work to reduce spills.
Natural Resources Wales has developed a good working relationship with Dŵr Cymru Welsh Water and liaises regularly to identify problems that could affect bathing water quality.
The outfalls from Oxwich and Overton Sewage Treatment Works are both approximately 2 kilometres either side of Port Eynon beach. Neither of these treatment works have been associated with bathing water quality failures. Work carried out at Oxwich STW by Dŵr Cymru Welsh Water has improved the quality of it's final effluent.
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.
It is possible the water quality at Port Eynon may, under certain conditions, be impacted by the Loughor Estuary, which has a substantial natural drainage catchment to the north of the area. The catchment is predominantly agricultural and the salt marshes are heavily grazed by sheep, horses and cattle. Brash and droppings, which are believed to have originated from the salt marshes, are occasionally seen on the beach after spring tides.
Phytoplankton (microscopic algae) naturally increase in number at certain times of the year. This process is known as a phytoplankton bloom. These algal blooms can occur at any beach during the bathing season and are usually noticeable by a surface scum. This beach has a history of such blooms.
A small stream runs on to the beach 500 metres to the east of the bathing water sample point. This stream is often dry in the summer months, but during periods of heavy rainfall is subjected to run-off from houses, roads and surrounding agricultural land around the bay.
Rain which falls on to the surrounding land, percolates through the rock fissures and reappears on the beach in the form of springs.
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. At Port Eynon Bay, data are available for the four year assessment period from 2015-2018. Sewage debris was observed in trace amounts on less than ten per cent of occasions. Animal faeces was not noted at this site. Trace amounts of litter were observed at the bathing water on between ten and twenty per cent of occasions. Oil and tarry residues were not noted at this site.
Poorly maintained private sewage treatment facilities could be a source of pollution, therefore the registration of all qualifying private sewage systems in Wales is required by 30 June 2012. The primary aim of this exercise is to provide increased protection for the environment and sensitive features such as bathing water beaches. Where discharges from properties are identified in the catchment that are not on mains sewerage, Natural Resources Wales will endeavour to ensure registration has been made, unless already a permitted discharge.
The natural drainage (hydrological) catchment surrounding Port Eynon comprises of steep sides, with a flat dune area behind the beach. A small stream runs on to the beach half a mile to the east of the bathing water sample point. This stream is often dry in the summer months. The limestone rocks in the area allow any rain falling onto the land to percolate through the rock fissures and emerge on the beach in the form of springs.
The majority of the land use in the catchment is sheep and cattle farming, with a small amount of arable farming. There are several static caravan and camping sites, holiday accommodation and small villages in the surrounding area.
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.