A striking video has emerged of a river turning milky white, sparking concerns for residents and farmers nearby.
Locals living in Yealmpton near Plymouth were shocked when they walked past the River Yealm to see its colour had completely changed on Monday, November 16.
Dr Chris Westwood and his wife Sarah shared the video on a community Facebook group, showing the chalky white-coloured water of the stream.
He told Plymouth Live : "We've been here nearly 40 years, and in the early days, it was quite a frequent occurrence for the River Yealm to be moderately white.
"This was only from time-to-time but it would happen a few times a year. The government are pushing for better, cleaner rivers, and sadly this shows that they're not getting much better, for a variety of reasons and a variety of pollutants."
Chris added that it was one of the worst he's seen in the past few years, adding it looked like "emulsion paint".
He was concerned that the pollution can cause damage to the surrounding ecosystems.
"What these leakages can do is remove oxygen from the water, meaning invertebrates could perish, and what it can also do is form a silt on the river bed which can snuff out plant life and so on," Chris explained.
"This sort of thing should be a preventable incident, and it just shouldn't happen."
Another resident, Simon Pearson, also captured a similar scene when he was walking at Quick Bridge, near Newpark Waste, Lee Moor, on Tuesday morning.
He wrote on social media: "By an amazing coincidence I know where this came from. Lots of clay works there and this stream joins the Yealm."
A spokesperson from the Environment Agency told Plymouth Live that they had received reports of the River Yealm running white on Monday afternoon.
They said: "An environment officer traced this to rainfall-related run-off at a quarry operation in the upper catchment, where action to stop the discharge had already been taken.
"Discolouration of the river was, fortunately, short-lived, and we are now considering what further action to take."