Bathing water profile - Thorntonloch

Last reviewed: 24 April 2025

Bathing water classification and sample results

Bathing water description

Thorntonloch bathing water is approximately 8 km to the south-east of Dunbar. It is approximately 1 km long and is popular with anglers and surfers. The sandy beach slopes gently towards the water and depending on the tides, there can be 0–250 metres before the water’s edge.

Site details:

Local authority: East Lothian
Year of designation: 1999
Water sampling location: NT 75384 74410

Risks to water quality

This bathing water is at risk of short term pollution following heavy rainfall. Bathing is not advised during or 1-2 days after heavy rainfall due to the risk to bathers’ health from water pollution.

Catchment description

A catchment of 16 km² drains into Thorntonloch bathing water. The area is mainly rural (99%) with grassland the major land use. Only 1% of the bathing water catchment is urban. There is no main town withing the catchment, but there are farms and smallholdings scattered throughout.

The main river within the bathing water catchment is the Thornton Burn (also known as Thurston Mains Burn).

There is one Site of Special Scientific Interest within the Thorntonloch bathing water catchment, Lammermuir Deans. It is designated due to the presence of scarce and declining habitats. The Lothian/Borders area was designated as a surface water Nitrate Vulnerable Zone in 2002.

View this Bathing Water on our interactive Map Service

Improving bathing water quality

Sewage

Whilst Scottish Water provides most water collection and treatment services in Scotland, there are no Scottish Water assets in the vicinity of this bathing water.

There are no other significant sewage discharges likely to threaten the water quality at this bathing water.

Agriculture

There are no impacts from agriculture affecting this bathing water.

Cyanobacteria (blue-green algae), algae and jellyfish

Marine waters are not at risk of cyanobacteria overproduction. This bathing water is not at risk of excessive growth of macroalgae (seaweed) or phytoplankton.

The possibility of increased jellyfish numbers in the water during summer months is a naturally occurring phenomenon. Most species common to the UK are harmless; the Marine Conservation Society advises to ‘look but don’t touch’.

Pollution incidents

Pollution can be reported via our website online form or by calling our 24 hours a day Pollution Hotline number 0800 80 70 60

If pollution is reported to us, or identified by our routine water quality monitoring program, we will investigate and where necessary work with others to remediate. We may contact other relevant organisations including the local authority, that local health board, Scottish Water and Scottish Ministers.

If there is a risk to human health the local authority is responsible for placing signs at the bathing water. Information will also be available on our website.

Everyone can help to keep the bathing water clean:

If you visit the beach with your dog clear up any fouling
Don’t leave litter or feed birds - this encourages unnatural behaviour, and they can pollute the water
At home, don’t flush wipes or other inappropriate items as these can block pipes and cause sewage spills