Weekly water samples are being taken at Queen Elizabeth Gardens, Salisbury – these are being tested for faecal indicator organisms (Intestinal Enterococci and Escherichia coli). Testing is being carried out by Mike D’Apice and funded by Surfers Against Sewage and follows the same methodology used by the Environment Agency.
Since May 2025, fifteen samples have been collected from the shallow section of the river adjacent to the play park in Queen Elizabeth Gardens. This is the area proposed as a new inland bathing water site.
E.Coli
Results have varied from less than 10 coliform-forming units per 100ml of water (cfu/100ml) up to a value greater than 1000. Using the classification methodology used by the EA this gives a 90th percentile value of 898, which would be classed as ‘Sufficient’ under the bathing water regulations. Most samples are below 400, which is reasonably low. One very high result (greater than 1000) is concerning, especially as it isn’t linked to rainfall. This might highlight a misconnection upstream.
Intestinal Enterococci
Results vary from less than 10 cfu/100ml up to 540, with a mean value of 266. Using the classification methodology used by the EA this gives a 90th percentile value of 1094, which would be classed as ‘Poor’ under the bathing water regulations. Based on the data collected so far this would suggest an overall status of Poor.
Classification
Classification is based on a statistical analysis of multiple samples (usually 20+) using the criteria here. Based on this, the data collected so far suggests a poor status, driven primarily by high IE levels. Often this points to human faecal inputs rather than agricultural. The nearest continuous treated sewage discharge to the river is at Amesbury, and is unlikely to have a significant effect on EC/IE levels due to fast breakdown time. There are combined sewer overflows in Salisbury, however these have not been reported to operate within the sampling timeframe.
Next steps
- Continue to take weekly samples
- Consider taking a series of upstream samples to try and highlight any potential sources of pollution
All data can be viewed here Citizen science results – Surfers Against Sewage • Data HQ.
