Severn Trent ramps up sewer monitoring

Severn Trent (SVT) has set out plans to install 40,000 smart sewer monitoring devices over the next five years following a successful trial with 1,400 of the units.

The company began the trial in Wolverhampton in September 2020 to prevent flooding caused by blockages from wet wipes and unflushables including fats, oils and grease.

The battery-powered devices use a hanging sensor to detect rising water levels with a tilt switch and communicate data back to the control room. If an alert is triggered, a team of engineers can respond to investigate and clear any blockages forming before a more serious incident occurs.

In a trading update this week, SVT said AMP7 started strongly for waste with 25 per cent fewer blockages and a 15 per cent reduction in pollution incidents.

The company said around 70 per cent of the blockages it clears annually are caused by domestic unflushables. Blockages caused by wet wipes and items being incorrectly disposed of cost the water industry more than £100 million each year as well as contributing to pollution and flooding.

SVT’s tactical asset planning manager, Margaret Williams, said the monitors provide teams with a clearer understanding of what is happening in the sewers in real time that allows them to react before blockages become a problem for customers or the environment.

Once installed, the low maintenance devices have a battery life of 10 years.

Williams said: “We believe they have the potential to play a key role in the early identification of blockage incidents caused by people putting the wrong things down the toilet and drain, which would be a fantastic outcome for everyone.”

For Q3 of AMP7 the company said its outperformance for outcome delivery incentives (ODIs) was on-track to increase beyond £50 million.

The trading update reported SVT’s best ever performance on water quality and against the Compliance Risk Index, as well as being ahead of its 80 per cent target for customer performance measures.