The River Cam at Sheep’s Green has ‘Designated Bathing Water’ status. This status is currently “Poor” with official advice against bathing (although it is still permitted).
This official status only gives a general overview of likely water quality, because is based on the previous 4 years of test results. However, to help you decide if you want to swim TODAY, you can see the results of the Environment Agency’s most recent test results at Sheeps Green here
Our General Advice
- Use your own judgement about when and where its safe for you to swim.
- Never drink water from the Cam (always keep your mouth shut when swimming)
- Dry off by vigorous rubbing with a towel.
- Shower as soon as possible after leaving the water, particularly if you’ve got muddy.
- Don’t swim just downstream of a sewage treatment works.
- Consider not swimming in the days after a period of heavy rainfall.
Don’t forget that some faecal presence in the river is natural.
Where and when to swim?
For several years, we have also been carrying out our own monitoring work, testing for E.coli upstream and downstream of Sheep’s Green.
Our results suggest that, of the swimming spots we have monitored, the water quality is best at Sheeps Green, Newnham Riverbank Club and the downstream end of Grantchester Meadows. It is slightly worse at the upstream end of Grantchester Meadows. It is frequently very poor at Byron’s Pool, which is only about 1km downstream of Haslingfield Sewage works. We are concerned about the health risks to kids paddling in the fish pass at Byrons Pool.
The improvement in the downstream swimming spots is more noticeable in the summer. We think this is because sunlight helps neutralise the bacteria and the river is flowing more slowly, giving the sunlight time to work.
Please note that levels of E.Coli should NOT be used as the only factor in deciding where or when it is safe for you to swim.
There may be nasty human pathogenic organisms in the river that bacteria counts don’t reveal, and we know that changes in the weather and rainfall will influence the results, sometimes suddenly and unpredictatably. For example, in times of high rainfall, some of the sewage treatment works above Cambridge discharge untreated sewage mixed with storm water into the river, leading to higher levels of contamination.
You can see more detail about our work towards achieving Clean Bathing water here