Located on the east coast of Anglesey, to the west side of Red Wharf Bay, the St David’s beach is sandy in nature. The beach is located in the Anglesey Area of Outstanding Natural Beauty and the Trwyn Dwlban Site of Special Scientific Interest. It is also 250 metres shoreward of the Menai Straits and Conwy Bay Special Area of Conservation. The water quality sample point is located in line with the beach entrance.
Investigations will be undertaken where and when necessary e.g. where there are elevated bacterial results in the bathing water that cannot be simply explained due to weather conditions.
There are no intermittent discharges that drain directly onto this beach or into the bathing water. Wendon Car Park Pumping Station overflow discharges into the sea, approximately 950 metres to the northwest of St David’s.
Dwr Cymru already provide information on spills from Pentraeth sewage works storm tank to the public via an app issued by Surfers Against Sewage. This sewage works discharges into the Afon Nodwydd upstream of Red Wharf Bay.
Natural Resources Wales has developed a good working relationship with Dŵr Cymru Welsh Water and liaises regularly in efforts to identify problems that could affect bathing water quality. Benllech Sewage Treatment Works had a primary treatment system installed in 1995 followed by further upgrades to provide secondary treatment, and an improved outfall. These improvements were completed in the autumn of 1999.
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 on the River Nodwydd or in Benllech.
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. Blooms of the algae Phaeocystis do occur along this coastline during warm and calm weather in May and June. This typically produces a cream or brown scum along the water’s edge, but is otherwise harmless.
Streams are typically affected by sewage or industrial run off from further up the catchment. There are no main rivers draining directly to the bathing area, but to the east of the cove, the River Nodwydd drains into Red Wharf Bay. At low tide, this flows within 350 metres of the bathing beach. The Nodwydd is a relatively small water body. It drains the catchment for approximately 2.5 kilometres, and there is no evidence to suggest that the river has any impact on 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 St Davids - Benllech, 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 over fifty per cent of occasions. Oil and tarry residues were not noted at this site.
Natural Resources Wales continues to work with private owners regarding potential pollution sources to the bathing water. There are a number of caravan sites in the area with private sewage disposal systems. Poorly maintained private sewage treatment facilities could be a source of pollution. There is a requirement for all private sewage system operators/owners in Wales to register for an exemption as is the requirement since 2012. The primary aim of this exercise was 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 primarily agricultural. The land rises up around the cove, with a caravan park and parking area located immediately behind. There are no main rivers draining directly into the bathing area, but to the east of the cove, the River Nodwydd drains into Red Wharf Bay. At low tide, this flows within 350 metres of the bathing beach.
The village of Benllech is located approximately 750 metres to the north west. The area immediately behind Benllech and south east towards St David’s is predominantly agricultural, with some isolated properties.
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.
