Waterhead bacteria samples

Weekly water samples taken at Waterhead, Windermere, by Ambleside Action for a Future's Waterhead E. coli Testing project, and the E. coli and intestinal enterococci counted in each. A sample is the water at that place at the time it was taken: not today's water, and not the rest of the lake.

For the risk from sewage spills on a given day, see SwimSignal's forecast for this spot. The forecast is worked out from rain and overflows, not from these samples.

2026

30 samples, 23 Mar 2026 to 12 Oct 2026. Mondays and Tuesdays. The laboratory, method and time of day are not yet confirmed.

E. coli: middle value 31.5, highest 649. Intestinal enterococci: middle value 10, highest 386. Per 100 ml.

2025

29 samples, 16 Apr 2025 to 30 Oct 2025. Mostly on Thursday mornings, analysed by Simplex Health's laboratory (the WET technical report, 17 Nov 2025).

E. coli: middle value 24, highest 388. Intestinal enterococci: middle value 12, highest 154. Per 100 ml.

What these samples do not tell you

• what the water is like now
• what the water is like elsewhere in Windermere
• a forecast
• a bathing water rating, which is worked out from many samples over four years, never from one
• that the water is safe to swim
• how well SwimSignal's forecast did: these samples have not been compared with it

How they were taken

Volunteers from Ambleside Action for a Future sampled the water at Waterhead, at the head of Windermere, about once a week from spring to autumn. Waterhead is not a designated bathing water, so the Environment Agency does not sample it. Each count is what the sheet records, per 100 ml.

Sources

Bacteria counts: Ambleside Action for a Future, Waterhead E. coli Testing (WET) project. The counts are public domain and are shown here with the project's permission. The project's own write-up is Tim Boden's Waterhead E.coli Testing (WET) Project Technical Report (17 November 2025).

• What this page's data holds, and what it may say
• The script that makes the file
• The samples as one file