Overflows had ‘no impact’ on water at weir, says company
Wessex Water has issued an explanation after reports of multiple people falling ill after swimming in Warleigh Weir near Bath.
During the July heatwave, some swimmers reportedly fell sick after going into the water at the popular beauty spot.
Wessex Water recorded two discharges from storm overflows near the weir on July 24, but a spokesman for the company insisted that it would not have had an impact on the water quality at the beauty spot during daylight hours.
Since April, Wessex Water has been carrying out a pioneering bathing water investigation at the weir, supported by the Rivers Trust, Environment Agency and landowner Johnny Palmer.
Sensors provide real-time data from storm overflow sites upstream of the weir.
Data for Saturday, July 24, shows there were discharges from two overflows near Warleigh Weir.
One took place at Monkton Combe for 18 minutes from 6.08am and another at Culver Street in Bradford on Avon for 16 minutes from 10.05pm.
There were no discharges on Sunday, July 25.
The river flow rate more than doubled between July 23 and 25 due to “intense rainfall”.
Amid the heavy rainfall, a spokesman Wessex Water said “these overflows would have had no impact on Warleigh during daylight hours that weekend.
“However, run-off from the wider catchment would have affected water quality. River water quality is affected by numerous factors including agriculture, urban runoff, treated effluent from public and private sewage works, storm overflows, misconnected drains and wildlife.”
With storm overflows becoming something of a hot topic, Wessex Water said there was a lot of confusion about how and why they operate. They act as a relief valve to protect properties from flooding when the combined sewerage system, which carries foul water and surface water, becomes overwhelmed.
When storm overflows are in use, Wessex Water notifies Surfers Against Sewage and other organisations.
The information is also published on Wessex Water’s website. The Environment Agency is sent information about when and for how long storm overflows are in use and also takes water quality samples to monitor bathing water quality.
Ruth Barden, Wessex Water’s director of environmental solutions, said: “In an ideal world, we wouldn’t have storm overflows at all, but separating out surface water will require enormous investment and disruption as pipework was laid under streets, homes and businesses many years ago. We also need a change in legislation to enable separation and local disposal of surface water straight back into the environment.”
Ms Barden added: “Right now, people need more information before deciding whether to swim, so we are working with stakeholders to develop a real-time water quality notification system so recreational users can enjoy the river with confidence.”
A health expert has also explained the dangers of open water swimming – including exposure to unclean water.
Senior clinical lecturer Dr Bharat Pankhania, of Exeter University, said: “Swimming in open rivers should be undertaken with much caution. There are many hazards under the water and rapid changes in depth and currents.
“Caution is also required after heavy rainfall and following dry periods. The advice is always to be aware of the hazards.
“It is well known that people can pick up infections if they ingest river, lake or sea water while swimming. Rivers can have high viral and bacterial loads due to run-off from agricultural land as well as regulated storm overflows and treated sewage discharges.
“It is not as simple as just saying the cause is one particular source in such complex environments.”