"Hundreds of litres" of have spilled into the River Derwent in Derby, and experts say a clean-up could take weeks.
Environment Agency officers were scrambled to the riverside after receiving calls from concerned passers-by at around 7am on Tuesday. Pollution was spotted beside the cycle path that runs along the side of the water into Derby - adjacent to the Pride Park industrial
Baiba Rūmniece, 29, from Chaddesden, was making her way to work in the former Derby Telegraph building when she noticed the spillage from the footbridge she was crossing.
Miss Rūmniece, of Meadow Lane, said: "I was walking past the river to work when I noticed - it was covering the river from one side to the other for about 20 metres. I was quite worried - it was such a long stretch.
"It's my usual route to work - I walk this way most days, but I've never seen anything like that before. It shouldn't be happening - it's putting the wildlife in danger - they could be poisoned because of this."
Baiba Rūmniece submitted these pictures she took of the oil in the River Derwent, near the Pride Park estate.
Officers set off in a boat from Pride Park to reach the site across the – where what is believed could be waste engine oil was leaking from a surface drainage system – where they worked to contain and soak up the spillage.
They used what is called a boom – a temporary floating barrier – to contain the spills. Workers in the boat then set about dropping absorbent polypropylene pads onto the water's surface to soak up the oil. The pads are designed to only soak up the oil and leave the water.
Site controller Paul Reeves, an officer for the Environment Agency, said: "We were alerted to which was on the River Derwent by a member of the public earlier on today and we've subsequently found it was coming out of a surface water drain down here, near to Pride Park.
"We're talking probably several hundred litres as an estimate at the moment. We've now got our people down here who are booming off the river to contain the oil close to where it's coming out into the river, and then the clean-up will continue from there.
"There is a bit of residue, which is unfortunate, but it's damage limitation – we've contained the majority of the oil. Once we've soaked up the oil we will collect up the pads, bag them, and dispose of them, but when we're dealing with this quantity of oil it's going to take a considerable amount of absorbents.
The incident happened near the cycle path along the river - adjacent to the Pride Park industrial estate. Graphic: Google Maps.
"We've got Severn Trent and their contractors working in the catchment to try and establish where the oil might have got into this drainage system. Severn Trent, who own this system, have got people working for them who are doing that now, so once we've got a bit more information we may well be able to go and see that.
"At the moment we're thinking it's probably waste oil-type substance, it's certainly not diesel – it's a thick, black oil which is very reminiscent of waste engine oil.
Environment Agency officers to contain the oil spillage. Photo: Environment Agency.
"There are clearly a number of water birds which live on this river, and if they get oil on their feathers they could be infected. We haven't seen any affected birds at the moment but what while our people are out in the boats, they will be patrolling up and down the river to see if any have been affected. Swans are likely the ones that would come off worse, but we are going to be checking that out.
"It's lucky that someone called in – if this had been left all of this would have gone downstream and could potentially have affected more wildlife. So between the call coming in and us getting the boom into the water I'd say we've had quite a reasonable response time we've had today and hopefully we've minimised the environmental impact and affect to any wildlife."
A spokesman for the Environment Agency said: "A significant petrochemical pollution incident is affecting around 1km of the River Derwent in the Pride Park area of Derby. We are working hard to minimise the potential impacts on the environment and have notified businesses who abstract water in or near the problem area to ensure they are adequately prepared.
"We have installed protective booms that will contain the pollution and stop it spreading further downstream and will continue using absorbent pads that are specifically designed to soak up the oil over the next few days. We are currently investigating the circumstances that led to this incident."
How long could the clean-up operation take?
Mr Reeves said: "It depends on whether the oil is still coming down, we don't know how much is still in the system in this pipework which stretches off way into the distance, so it could take anything from a few days, or maybe a few weeks, depending on the volume.
"We're not got much rain at the moment, so a bit of rain could force the oil down – so in some respects we could do with a bit of rain to help speed things along. I can't give a very good estimate of how long it will be, but it could potentially take weeks.
Environment Agency officers working to contain the oil spillage. Photo: Environment Agency.
"Once we've got it contained we'll be able to remove the with absorbents or whatever other methods we may wish to use.
"It's been quite a difficult trying to get the boat and all of the equipment into the water, so I think we've done a fairly reasonable job. We launched the boats down at Pride Park, which is the only place we could realistically get the boat into the water, because the banks are quite steep here. It was quite a drama – we had quite a few weeds and bits to chop back to clear a path to get to the river."