This is a small, sheltered, sandy bay, named after the River Saith, which cascades as a waterfall over the limestone cliffs onto the north of the beach. Facing north west, the bay is relatively small, at approximately 250 metres wide. The coastal waters and coastal belt is designated as Cardigan Bay Special Area of Conservation, confirming the high conservation status of the area. The water quality sample point is located to the centre of the beach.
Natural Resources Wales continues to work with Ceredigion County Council and Dŵr Cymru Welsh Water to establish sources of pollution around the beach.
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).
Tresaith is potentially impacted by one storm, emergency outfalls on the foreshore, particularly during periods of heavy rainfall. This protects domestic properties from being flooded by sewage, during heavy rainfall. However, sewer overflows operating during and following heavy rain, can result in a fall in the quality of bathing water at Tresaith.
In recent years, telemetry equipment has been installed in most of the overflows by the water company. This technology has allowed Dŵr Cymru Welsh Water to respond to warnings of blockages in the sewage system and has reduced the number of actual and potential overflows.
A project known as Event Duration Monitoring (EDM) is underway to install telemetry on Combined Sewer Overflows (CSOs) within 2km of a bathing water by 2020 so that Dŵr Cymru Welsh Water (DCWW) know when the CSOs are operating and can work to reduce spills. One CSO near Tresaith is included in the project.
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.
Natural Resources Wales and Ceredigion County Council have been working together to improve the bathing water quality at Tresaith for a number of years.
Wrongly connected waste water pipes can affect the water quality of rivers and the sea. Natural Resources Wales has worked with Ceredigion County Council and Dŵr Cymru Welsh Water to trace the sources of pollution from household toilet and utility misconnections to the private and public surface water systems, discharging into Tresaith bathing waters.
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.
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 does not have a history of such blooms.
Streams are typically affected by sewage or industrial run off from further up the catchment. Tresaith is influenced by the River Saith, which flows into the northern part of the bathing water. High flows in streams, rivers and sewers due to heavy rainfall affects water quality in the bay.
Sewage from Tresaith is pumped to the Sewage Treatment Works at Aberporth. This discharges directly offshore at Aberporth, to the south of Tresaith. Disinfection through membrane filtration treatment of the effluent protects bathing water quality.
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 Tresaith, data are available for the four year assessment period from 2020-2023. Sewage debris was not observed at this bathing water. Animal faeces was not noted at this site. Trace amounts of litter were observed at the bathing water on less than ten per cent of occasions. Oil and tarry residues were not noted at this site.
Pollution prevention visits have been undertaken by Natural Resources Wales at agricultural premises throughout the Saith catchment. As part of this process, Natural Resources Wales assessed slurry and manure storage, and potential sources of contamination from farm yards which could adversely impact bathing waters. Advice and guidance has been given to farm owners about responsibly managing nutrients, and where needed, improvements are identified and implemented through voluntary and regulatory means.
Natural Resources Wales continues to work with private owners to address potential pollution sources to the bathing water. This work involves where necessary, advisory mail drops, dye tracing, misconnection surveys and face to face meetings.
Poorly maintained private sewage treatment facilities could be a source of pollution, therefore the registration of all qualifying private sewage systems in Wales was 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 the bathing water is predominantly agricultural. The River Saith, along with two other streams, located a mile either side of Tresaith, are likely sources of diffuse run off, as they drain an agricultural catchment several miles wide.
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.
