An environmentally-friendly herbicide is keeping tracks and taps flowing up and down the country thanks to a partnership between water companies and Network Rail.

Eight ‘spray trains’ cover hundreds of miles every night to prevent over-growing plants and weeds – and ice when temperatures drop – from disrupting train services.

Thames Water was one of the first water companies to work with Network Rail’s predecessors to ensure the chemicals used did not pollute waterways, which often run parallel to rail lines.

The project was first launched in London and the Thames Valley in the 1990s, but since then has expanded to create an agreement for the benefit of all water companies across England and Wales.

Dr Dinah Hillier, a Thames Water Scientific Services manager, said:

“We’ve worked closely with Network Rail to influence the types of herbicides they use and how they’re applied so they are less likely to contaminate water, and we’re delighted with the results.

“It’s imperative whatever is used to kill the weeds doesn’t disrupt rail passengers or impact water quality, particularly where they are used as drinking water sources. We’re proud custodians of the environment and are always looking for more ways to protect and enhance it, and this is a great example of how working collaboratively with other industries can make a big difference.”

Dr Hillier represents Water UK, the industry body, on the railways initiative, which in 2016 was turned into a memorandum of understanding between Network Rail, Water UK, the Environment Agency and Natural Resources Wales.

The agreement now protects more than 600 vulnerable drinking water sources from herbicides that, if they reached the water, would require removal using expensive and energy-intensive advanced treatment processes.

Rossa Donovan, head of environment and sustainability at Network Rail, added:

“Management of plant growth across the whole of our 50,000 hectare estate is essential to make sure that activities like inspections can be undertaken safely.

“This agreement enables us to demonstrate a commitment to using herbicides responsibly and has been a key part in our justification for the continued, and safe, use of chemicals on the network.”

As part of its future plans for 2020-25, Thames Water has dedicated an additional £1.1 billion for activities to protect and enhance the environment, including an innovative multi-pronged Smartter Water Catchments initiative, an 18 per cent reduction in pollutions and a commitment to generate enough renewable energy to power the equivalent of 115,000 homes.