Severn Trent is to bring forward plans to clean up rivers by 16 years after the Government and regulators launched an investigation into whether sewage works are breaking environmental rules.

The company said that it would meet obligations to improve rivers under the Environment Act within nine years, rather than the previous quarter-century timeframe.

“There has been much discussion recently about the quality of our rivers and coastline,” the company said

“Rivers are key to our supply chain and, although we don’t own our region’s rivers, we take our role in protecting and caring for them seriously.

We’ve continued to invest significantly in our network, in our people and to support our strong commitment to the environment

“Our rivers are currently the healthiest they have been since the Industrial Revolution, but more needs to be done.

“That is why we plan to fulfil all our actions set out in the Environment Act to improve river quality in a nine-year timeframe, rather than the 25-year target.”

The company said that it would work with farmers and sectors of the economy that have the biggest impact on the health of the UK’s rivers.

Severn Trent said that it welcomes the opportunity to work with regulators following the announcement of an Ofwat and Environment Agency investigation into sewage treatment plants.

The regulators said that companies may face unlimited fines if they are prosecuted for breaches of their environmental obligations.

They launched the probe into more than 2,000 sewage works after new monitoring equipment revealed that many sites may not follow the rules on how much wastewater is treated before it can overflow into nature.

Severn Trent also revealed a 13.8% hike in pre-tax profit in the six months to the end of September.

It made £256 million on revenue of £958 million, up 8%.

“We’ve made another strong start to the year as we focus on delivering for stakeholders across our region and delivering for customers in the areas that matter most to them, all while driving the financial performance of our business,” said chief executive Liv Garfield.

“We’ve continued to invest significantly in our network, in our people and to support our strong commitment to the environment.

“Our environmental ambitions remain at the heart of our company, whether planting over a million trees, reducing our carbon emissions, or producing an extra 95 million litres of water to tackle the threat of water scarcity.”