An environmental watchdog is investigating the suspected pollution of a river by Scottish Water which has left a “significant” number of fish dead.
People have been advised not to swim or fish in the River Devon in Clackmannanshire until the results of the investigation are known.
Scottish Environment Protection Agency (Sepa) officials went to look into a pollution complaint early on the afternoon of Monday July 4 and found Scottish Water workers trying to clear up an acid spillage.
It is thought the pollution happened on the Sunday afternoon.
Sepa said the incident has resulted in a “significant fish kill” of a variety of species in a stretch of the river.
It has informed its partner agencies Clackmannanshire Council, Perth and Kinross Council and NHS Forth Valley.
A Sepa spokesman said:
“The source and cause of the pollution is being investigated and steps taken to try to minimise the impact on the local water environment.
“Sepa staff attended the site and took water samples and a Sepa ecologist also worked on site with the local team to assess the environmental impact.
“Sepa quickly informed partner agencies and has been working closely with them throughout the investigation to assess the impact on the environment.
“The results of our investigations have been passed on to the relevant public health authorities to assist with their considerations of public and animal health.”
Sepa said Scottish Water formally notified it about the spillage incident late on Monday afternoon.
The environmental organisation said the investigation could lead ultimately to a report being submitted to the procurator fiscal.
A Scottish Water spokesman said:
“Scottish Water is working closely with Sepa to investigate a pollution incident in the River Devon.
“We cannot comment further at this stage. Those requiring further information should contact Sepa directly.”
WWF Scotland director Richard Dixon said:
“Any spill of acid is serious but there has been a strong effort over the last decade to return stretches of the River Devon to a more natural state, so this major pollution incident is particularly unfortunate.
“We also need to ask why it seems to have taken 24 hours for Sepa to be notified of this incident, since time is always of the essence in heading of the worst consequences of a pollution event.”