Residents 'in shock' after Plymouth river 'turns orange'

The Environment Agency is investigating after residents reported the River Plym had turned a 'rusty' orange colour. Credit: Danny Slater Elsey

Residents in Plymouth say they were left in shock after a river in the city 'turned orange'.

The Environment Agency is investigating after passers-by reported the River Plym had changed colour.

One resident, Danny Slater Elsey, said he was walking his dog with his children when he approached the "rusty orange" river", leaving him "shocked at the sight".

"The very next day we decided to have another walk around the Burrator Reservoir only to see the same orange rusty water coming down the waterfall there", he said.

A spokesperson for the Environment Agency said: “We are aware of an incident on the River Plym and Tory Brook in Plympton which caused some discolouration to these watercourses on 25 July.

“Our Environment Management Teams is currently investigating the cause of the pollution and will take necessary steps if required."

They added that environmental incidents should be reported to a 24/7 hotline on 0800 807060.

People first noticed the change in colour at the weekend, and some reported the discolouring to the Environment Agency hotline. Credit: Danny Slater Elsey

The River Plym's source is about 450m above sea level on Dartmoor, at Plym Head. It meets the River Meavy and then run south towards Plymouth Sound, through Plymbridge Woods. The upper reaches contain antiquities and mining remains, and it also flows past clay workings at Shaugh Prior.

The change in colour could be down to iron discharge. Heavy rain can result in ‘blowout’ of iron oxide deposits. Orange water discharge is referred to as Acid Mine Drainage.

The water contains tiny orange particles made up of iron, oxygen and hydrogen. The particles form as a result of chemical reactions between water, dissolved oxygen in the water and iron sulfide rock.