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.