Should you take the plunge? How to tell how clean the sea is

Several factors can influence the cleanliness of sea water, leading to concerns among beachgoers. These factors include sewage spills, heavy rain, agricultural run-off, urban pollution, and wildlife. While a sewage spill doesn't automatically mean water quality has been affected, the absence of an alert doesn't guarantee clean water either.

In England, more than a third of designated bathing waters are located in Devon and Cornwall, including popular beaches such as Sennen Cove, Porthcurno, Fistral, Bigbury-on-Sea, and Croyde Bay. The Environment Agency rates bathing waters from "excellent" to "poor" based on bacteria levels found in water samples collected over a four-year period.

The testing, however, only occurs during the bathing water season (May 15 to September) and at sites already designated as bathing waters, providing no information about conditions on specific days. Surfers Against Sewage (SAS) argues the current system isn't suitable as people use beaches year-round. To address this, SAS has developed an app that offers alerts when bathing water quality might be impacted by pollution, including sewage spills.

This alert remains active for 48 hours post-discharge, providing users with a precautionary approach. Water companies also supply information on when bathing water quality could be affected by sewage spills. For instance, South West Water's WaterFit Live displays an alert for 12 hours and 30 minutes after a spill concludes. The Blue Flag scheme assesses beaches against strict criteria, including water quality, environmental management, safety, accessibility, and environmental education.

Some Blue Flag beaches include Carbis Bay, Summerleaze, and Polzeath in Cornwall, as well as Exmouth, Sidmouth, and Blackpool Sands in Devon. Meanwhile, community groups like Friends of the River Teign are testing pollution levels at beaches, rivers, and waterways, providing more frequent and localized water quality information.