London mayor Sadiq Khan has called for more government cash to tackle road run-off after a ‘pioneering’ new study found that it is a significant pollution risk to the capital’s rivers.
Research funded by Mr Khan and the Environment Agency found that all of the roads involved in the study have the potential to damage local rivers but modelling showed that roads where HGVs regularly apply their brakes are often the worst affected.
This is usually around junctions, roundabouts and traffic lights.
The mayor’s office said this is the first time dedicated research has been carried out to identify sources of run-off, which occurs when pollutants such as residue from oil spills and tyre and brake wear from vehicles build up during dry weather and are washed into rivers and streams when it rains.
It added that the problem is likely to increase with the effects of a changing climate.
Mr Khan said: ‘This report provides clear evidence that pollution from the surface of London’s roads is posing a significant risk to our rivers.
‘We’re working with partners to find solutions that prevent water contamination, but the Government must step up to provide the Environment Agency and highways authorities with the appropriate funding for these measures to properly protect the capital’s rivers.’
Road run-off can carry over 300 pollutants and can kill fish and turn river water black.
Only one of London’s 41 bodies of water is classed as ‘good’ under the EU Water Framework Directive.
The mayor’s office said that while he has no direct powers over water quality, his staff have been working with partners on the research ‘to help drive action’, including using sustainable drainage and creating wetlands to help filter out the worst pollutants before they reach rivers.
The most polluting roads identified in the study include:
- Junction of North Circular (A406) and Abbey Road, Alperton
- North Circular at Chingford
- Slip road to the A40 (B456) by Ealing Sports Ground
- Jenkins Lane, Beckton
