Visitors to Clatto Reservoir in Dundee have been told to avoid contact with the water as it has been infected by dangerous bacteria for the third time in 12 months.
Recent sampling has identified high levels of blue-green algae and until the all clear is given people are being asked to avoid contact with the water and keep their pets away.
When in high concentrations in the water this naturally occurring algae can multiply to cause algal blooms which may then release toxins.
The behaviour of algae is erratic and the levels of its toxicity can fluctuate. It can appear one day, be dispersed by the wind and re-accumulate at any time.
Contact with algal scum or water close to it can cause skin rashes. More serious health effects can include stomach upsets, eye irritations and pain in muscles and joints. These symptoms are usually mild, but in some cases can be severe.
If anyone has been in contact with the water and experiences health problems they should contact their GP or NHS 24 on 111
Notices have been posted at the reservoir.
It is the third time in a year that the algae has infected Clatto Reservoir. Warnings were issued last June and then again in April.
Dundee City Council environment convener councillor Craig Melville said: “Due to the high concentrations of blue green algae, parents are advised to be vigilant with their children and dog owners should prevent their dogs from drinking the water.
“Our officers will continue to monitor the quality of the water and notices will be removed when the hazard has passed.”
Dundee City Council’s environment department can provide further information on the algae on 433710.