2014 Bathing Water Profile for Swansea Bay

  • The Bay is wide and sweeping, measuring some 9 kilometres in length, from Mumbles Head in the west, to the River Tawe in the east. The beach faces south east towards the Bristol Channel and is backed by the urban area of Swansea. The beach slopes gently and comprises of sand, pebble and mud flats. At low tide the waters are shallow and a long distance from the shore front. The water quality sample point is located at the east of the Bay, opposite the Guildhall.
  • Swansea
  • Natural Resources Wales works to establish sources of pollution around Swansea Bay. Some of this work is carried out in partnership with the City and County of Swansea 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 1st of May) and mid-season (during the bathing water season). Natural Resources Wales, Aberystwyth University and City and County of Swansea are working together on the Smart Coasts project funded by Interreg to the tune of 2 million euro. The project has started a bacterial source apportionment study into the sources of bacteria in the Swansea Bay area. One of the aims of the project is to determine the cause of reduced water quality in Swansea Bay. In 2011 and 2012, blackbox modelling data acquisition, source apportionment data acquisition and offshore studies were carried out. The data is still being analysed but preliminary results have been presented to the partners by the project. These results have already been used to target our pollution prevention investment for 2013.
  • Swansea Bay is potentially impacted by numerous storm, emergency and surface water outfalls, both along the foreshore and within the main freshwater streams, particularly during heavy rainfall. In the catchment of Swansea Bay, there are numerous storm, emergency and surface water outfalls, that discharge into the Tawe River. These protect domestic properties in Swansea and Mumbles from being flooded by sewage during periods of heavy rainfall. However, sewer overflows operating during and following periods of heavy rain can result in a deterioration in the quality of the water in the River Tawe and at Swansea Bay bathing waters. 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 sewerage system and has reduced the number of actual and potential overflows. DCWW are currently developing a solution to decrease the number of spills to the designated bathing water from the sewerage network. Key assets have been identified and the solution is likely to focus on surface water reduction and network alterations. The cost of these solutions is likely to be significant and will be met through the AMP programme. It is hoped that work will be completed by the end of 2016.
  • In 1999, the Swansea sewer system was significantly upgraded and a new wastewater treatment system was installed at Fabian Way. This resulted in a vast improvement to the water quality in Swansea Bay. Since then, Natural Resources Wales has worked with Dŵr Cymru Welsh Water to make further improvements to the sewerage system and Swansea Wastewater Treatment Works.
  • Natural Resources Wales and the City and County of Swansea have been working together to improve the bathing water quality in Swansea Bay for a number of years. In 2010, Natural Resources Wales and the City and County of Swansea entered into a collaborative agreement to progress with this work by carrying out a misconnection survey in the Swansea Bay Area over 2010/11. This work, notably in the river Clyne and Cwm stream catchments, has continued into 2012/13.
  • This bathing water does not have a history of large amounts of seaweed (macroalgae).
  • 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 has a history of such blooms.
  • 2014 Bathing Water Profile for Swansea Bay
  • Streams are typically affected by sewage and industrial run off from further up the catchment. Swansea Bay is mainly influenced by the Rivers Tawe and Clyne. There are also numerous small streams and over 25 surface water drains which empty into the bay. These can be a source of reduced water quality after periods of heavy rainfall.
  • Swansea Wastewater Treatment Works discharges offshore to the east of Swansea Bay. Disinfection through ultra violet treatment of the effluent protects the quality of the bathing waters. Afan Wastewater Treatment Works also discharges offshore, further east towards Aberafan.
  • Natural Resources Wales is working with a number of private owners regarding potential pollution sources to Swansea Bay. This work involves 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 highly urbanised, with a busy retail and light industrial sector located along the lower reaches of the River Tawe. The upper reaches of the catchment are predominantly agricultural.
  • 2014 36900:1

    • 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 England and 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 the Environment Agency and 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. At Swansea a unique model has been developed by the Smart Coasts Sustainable Communities Project that predicts water quality at the designated bathing water. The model is run during the Bathing Water season and the prediction is used to let people know if the water quality is good or poor. This information is provided by way of a sign on the slipway to the beach, on the City and County of Swansea’s website and via twitter. The prediction is updated 3 times a day during the week and twice on the weekend. Last year the sign said good 52% and poor 48% of the time. There are 139 days in the bathing water season. On 37 of those days the sign stayed good all day. On 46 days the sign had to be changed to poor once and on 25 days it had to be changed to poor twice. On 31 days the sign stayed poor all day. Daylight improves water quality so, generally, water quality improves as the day goes on. For Swansea Bay’s bathing water predictions go to http://www.swansea.gov.uk/index.cfm?articleid=29433 or follow @SwanseaBayWater on Twitter.
    • Discharges from sewage treatment works have improved substantially in England and Wales since the 1980s.

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