A combination of oil, chemicals, and tyre particles from roads is contaminating English waterways, and there is no regular monitoring of this pollution, according to a BBC investigation. Heavy rainfall causes these pollutants to flow into rivers and streams, causing significant environmental damage. The major road network in England, managed by National Highways, consists of over 18,000 drains or outflows. The Environment Agency, responsible for monitoring water pollution in England, admitted that it does not regularly monitor this runoff, although it does test for road pollutants during general water monitoring.
The runoff from highways and urban areas is a serious issue, accounting for 18% of water quality failures in England. It is the third most damaging source of water pollution after agriculture and sewage. Campaigners have conducted their own tests and found micro-plastics, heavy metals, toxic chemicals like arsenic, and carcinogenic compounds from car tyres in the water.
Prof Alex Ford from the University of Portsmouth highlighted that some of these contaminants can damage DNA, affect the nervous system, and cause cancer. The Environment Agency can issue permits for activities that may cause pollution and set limits on the pollution levels. However, it has chosen not to issue permits for outfalls, arguing that it would not reduce pollution.
National Highways is aware of the problem and is using a computer model to identify high-risk outfalls. It has identified 1,236 potentially high-risk locations and expects around 250 to be high-risk after verification. However, mitigation measures will only be in place at about 30 of these sites by the end of 2025, a pace that a committee of MPs has called “unacceptably slow”.
One mitigation measure is a reed bed built by National Highways off the A38 in Devon at a cost of about £2.5 million. This reed bed filters runoff from the busy road. The next step is to dredge the lake of all the heavily polluted silt that remains at the bottom.