‘Insufficient’: Plan to fix toxic road runoff confirms measures for just 0.3% of problem sites

More than 1,000 outfalls managed by National Highways could carry a high risk of toxic road-runoff entering water bodies, a plan published by the roads body reveals, however the agency has only confirmed funding to improve four.

The National Highways 2030 Water Quality plan sets out a target to locate and verify assets, meaning soakaways and outfalls, that have a high risk of harming the environment by 2030, as per its Environmental Sustainability Strategy. 

Soakaways are drainage systems for road water run-off and outfalls are the discharge point of that waste stream into a body of water. 

The plan also states that it aims to “maximise delivery opportunities” to carry out mitigation at the high risk locations which are verified, and set a baseline and target level of delivery for 2025 to 2030.

National Highways is responsible for 25,758 soakaways and outfalls in total, with the plan outlining that 5% are estimated to be at high risk – 1,236 in total –  79% are deemed to be at low or medium risk, and 16% are deemed to have had the risk addressed. 

Of the assets deemed to be at high risk, 254 have been estimated to need mitigation work, and 145 of these have been confirmed to need this work. 

In the plan it is proposed that between now and 2025, risks at only four high risk assets are set to be mitigated by National Highways, which means that there are funded plans to provide mitigation at just 0.3% of the high risk sites estimated to exist, and 2% of those which have been estimated to need this work.

A further ten could be mitigated using funding for road projects that are currently ongoing and have been funded, but may take longer to complete, and 17 high risk sites to be mitigated during this period subject to more funding. 

National Highways confirmed to ENDS that by 2030 it aims to address all of the high risk outfalls that have been verified, and further sites identified over the course of the plan, subject to funding for its next Road Investment Strategy from 2025. 

In Annex D to the report, where the risks and control measures are identified, it states that National Highways is at a “high inherent risk” of not being able to meet the targets it sets out in the report due to “uncertainty” regarding funding for the Road Investment Strategy 3, which covers 2025-2030.  

An “increased reputational risk to National Highways from adverse media commentary on approach to address high risk pollution locations” was also included in this risk assessment, which it suggested mitigating through an annual reporting of improvements made, the publication of Water Quality Plan on its website, and the development of communications plan. It also raises concerns about whether there will be sufficient in-house resources to carry out the plans and report whether the projects are working. 

Criticism has been raised about the pace of change, and the fact further ambition relies on new funding. 

Director of operations at Stormwater Shepherds UK, Jo Bradley – who worked for the Environment Agency for 28 years and is an expert on water quality and pollution – described National Highway’s plans as “insufficient”. 

She told ENDS that the government-owned company should be mitigating “100 outfalls and soakaways a year at least”. 

She continued: “There is plenty of money in their Environment & Wellbeing Fund, but they need to direct more of it to the prevention of [water] pollution. They can deliver good and effective schemes but they are just not moving fast enough.” 

Dr Laura Foster, head of clean seas at the Marine Conservation Society, said that the plan “doesn’t meet the scale of ambition necessary to tackle harm caused by road runoff”. 

She continued: “Road runoff contains chemicals, some of which have been found to have a known and negative impact on the environment and wildlife. 

“National Highways should be preventing the release of harmful chemicals into the environment to mitigate against any potential harm."  

A previous ENDS investigation revealed that widespread toxic road runoff has been “brushed under the carpet”, with the Environment Agency doing “very little” to limit the impact despite discharges found to be well above the legal limits for copper, zinc, lead and polycyclic aromatic hydrocarbons (PAHs) as set out under environmental quality standards.

Stephen Elderkin, director of environmental sustainability at National Highways, said: “National Highways wants to see a connected country and a thriving environment. 

“We are committed to addressing all of our high-risk water outfalls by 2030 and our Water Quality Plan 2030 sets out a high-level programme of work to achieve this. 

“As part of our continued commitment to protecting the water environment, National Highways has also invested in a programme of research to understand the risk of pollution from microplastics in road runoff.”