Measuring approximately 600 metres in length and facing south into Cymyran Bay, Silver Bay is a sandy beach located on the west coast of Anglesey. The land surrounding the bathing water is partly forested, contains Silver Bay Holiday Park and has areas of farmland. A Royal Air Force base is located to the east on Anglesey. The bathing water is located in the Anglesey Area of Outstanding Natural Beauty and lies between the Beddmanarch-Cymyran Site of Special Scientific Interest and the Glannau Rhoscolyn Site of Special Scientific Interest. The water quality sample point is located in the centre of the bay.
Natural Resources Wales works to establish sources of pollution around Silver Bay. 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).
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.
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.
Streams are typically affected by sewage or industrial run off from further up the catchment and can be a source of reduced water quality, after heavy rainfall. The bathing water is not influenced by any freshwater sources.
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 Silver Bay Rhoscolyn, data are available for the four year assessment period from 2014-2017. 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. There was one observation of tarry residue at the site in trace amounts in May 2014 but otherwise oil and tarry residues were not noted at this site.
Silver Bay Holiday Park has a consent to discharge treated effluent approximately 1 kilometre from the bathing water. There is no history of non-compliance with their consent and the discharge is not known to have any impact on the bathing water quality.
Poorly maintained private sewage treatment facilities could be a source of pollution, therefore the registration of all 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 properties are identified in the catchment that are not on mains sewerage, Natural Resources Wales will endeavour to ensure registration has been made.
The natural drainage (hydrological) catchment surrounding the bathing water is comprised of rural land. There are no direct surface or foul discharges to the beach, only runoff from the surrounding forest and farm land.
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.