The Environment Agency has said it is investigating reports of foam in the River Wye between Buxton and Bakewell.
The Midlands department of the Environment Agency shared images on social media of the foam.
A tweet from the Environment Agency on Twitter said it was working with Severn Trent to investigate it further.
The tweet added: "We haven't see evidence of any impact on the environment or wildlife caused by the foam but we will continue to monitor the river. The fish seem happy at the moment!"