Bathing water quality testing for Healing Waters events

For outdoor swimming events in the Healing Waters project we test the bathing water quality of the water for swimming, so that we can assure participants that we are doing everything to make sure they are safe. The result only tells us that the water is of a certain bathing water quality on the day the sample is taken. However it can be useful in building up a picture of bathing water quality in our Brecks rivers and waters. (Note that this is not about testing the ecological water quality, more relevant for wildlife.)

Testing before events for bathing water quality

In planning and progressing this lottery funded project we have to be very careful to ensure such work is done to a high professional standard. The company was selected to use for the bathing water quality tests after researching and receiving several recommendations by swim event and venue organisers.

Swim Safety ( provides a range of water quality testing and analysis services for a large number of open water swimming and triathlon events and venues in the UK.

The company advises on timing and location, provides the sampling kit, and gives instructions for taking samples. This is to go out into the water and take the sample from 30 cm below the surface in the sealed bottle/s provided, closing it immediately and taking it as soon as possible to the Post Office to send off with the provided label. If necessary, refrigerating it on the way.

The samples are taken by the project lead together with other volunteers, and usually combined with other risk assessment, measuring or other necessary procedures in preparing for the event. And we take photographs of the process of taking the samples and doing other preparatory work, partly because it is good to show volunteers doing these tasks, also because the lottery funder requires us to document what we do.

swimmer in water

The samples are posted to the lab and the result is emailed back after a few days as a certificate. This gives the raw data and aligns the results to EU bathing water directive standards (, those that apply to officially designated bathing waters, monitored by the Environment Agency in England,

The tests are for Total Coliforms; E. coli; Faecal Streptocci / Intestinal Enterococci, and are done in accredited UKAS laboratories.

The EU directive sets levels for these bacteria to be categorised as ‘Excellent’, ‘Good’, ‘Sufficient’ or ‘Poor’. So far all Healing Waters event venues or potential venues that we have tested have received ‘Excellent’ results.

(River Thet, Thorpe Woodlands, August 2020; river Lark, Mildenhall Jubilee Fields, May 2021; Lynford Water public lake August 2021; river Thet, Thetford Riverside, August 2021; Lynford Water public lake Sept 2021; Mildenhall May 2022; Lynford June 2022, Lynford June 2023, Brandon Staunch August 2023.)

Certificates available on request, or to download, see below.

One off blue green algae test

In August 2021, following the visual identification of a tiny amount of potential blue green algae at Lynford Water public lake, the venue for the August event, we organised a test for this, using the same company and their accredited lab, and as they explain on their website, they provide the raw result data and also align the results to the World Health Organisation (WHO) guidelines for blue-green algae.

The WHO guidelines are contained in ‘Guidelines for safe recreational water environments. Volume 1, Coastal and fresh waters’ available from here, In Chapter 8, downloadable here,

Those guidelines set the potential impact on human and animal health of cyanobacteria, with the lowest level being anything above 20,000 parts per millilitre. Anything below that is not considered harmful.

A sample taken 9 August was tested, and the certificate giving the result states that no blue green algae was detected in the water. It refers to other non-harmful/beneficial algae and microorganisms (colonial green and colonial golden algal species and a number of rotifer species).

Certificate available on request, or to download, see below.

All certificates available to download:

swims and swim places, and related issues