In 2025 there were concerns from many quarters about the high levels of E. coli in the Ver, especially in the Flamstead area when sewage has been discharged directly into the river. In Verulamium Park too, parents and dog owners have been worried about playing in the river, especially in the summer months.
To offer improved factual support, the Society has begun regularly testing the River Ver for E. coli using an ALERT One analyser, which gives quick results and removes the two-week wait for lab scores to come back. Although the results cannot give a categoric ‘all clear’ they will, at least, give river users a guide to water quality at a fixed point in time, at a specific site. This unit was used during the 2022 Paris Olympics to test the Seine before events in the river and is now being used by groups like River Action to test the Thames and Wye.
In 2026, to achieve a better understanding of our local river, we began monthly testing in March, downstream of the Lake in Verulamium Park. In June, water quality began to decline noticeably following very hot weather, rather than any known sewage spill. Consequently, we have introduced weekly testing to get a more regular record of the situation.
The E. coli standard for ‘inland bathing waters’ is measured in colony forming units (cfu) per 100mL. Less than or equal to 500cfu is ‘excellent’ and over 900cfu per 100mL is ‘poor’ and below the standard for bathing. However, there are no designated ‘bathing waters’ on the Ver as such and there are no pass/fail standards for individual water samples – official classifications are based on a range of samples. Nonetheless, our scores do at least give some perspective to the quality of the river water.
| Date | Site | E. coli cfu per 100mL |
|---|---|---|
| Wednesday 11 March | Verulamium Park d/s Lake | 25 |
| Thursday 2 April | Verulamium Park d/s Lake | 163 |
| Thurs 30 April | Verulamium Park d/s Lake | 114 |
| Thurs 21 May | Verulamium Park d/s Lake | 441 |
| Thurs 18 June | Verulamium Park d/s Lake | 5347 |
| Friday 19 June | Verulamium Park d/s Lake | 1242 |
| Sunday 21 June | Verulamium Park d/s Lake | 2379 |
| Thursday 2 July | Verulamium Park d/s Lake | 769 |
| Thursday 9 July | Verulamium Park d/s Lake | |
| Thursday 16 July | Verulamium Park d/s Lake | |
| Thurs 23 July | Verulamium Park d/s Lake | |
| Thursday 30 July | Verulamium Park d/s Lake |
The Ver Valley Society conducts E. coli tests and shares results so that river users can be informed about water quality. All tests are conducted in good faith. Although test results can provide a general guide to water quality and trends, no liability can be accepted by the Society, its volunteers or any organisations with which we work, for any harm or damage suffered by any person or pet as a result of relying on the information shown on our website or elsewhere.
All users of the River Ver should make their own assessment of the safety of using the river for recreational purposes.
The results of water quality testing, are provided without any guarantees, conditions or warranties as to their accuracy. To the extent permitted by law, we and third parties connected to us expressly exclude all conditions, warranties and other terms which might otherwise be implied by statute, common law or the law of equity.