United Utilities ends need for harsh chemicals in phosphorus removal

United Utilities has become the first water company in the UK to adopt an innovative plant-based method of phosphorus removal that coagulates solids suspended in wastewater. 

In removing excess phosphorus, the water company said its new process addresses “the most common cause of water quality failure in England and Wales”. It said UK water companies currently spend some £39m a year on metal-based chemicals to remove phosphorus, “with demand and prices rising”.

It added: “Chemical processes pose a particular challenge for small, rural sites, which have higher relative investment needs for phosphorus removal and limitations in terms of site size, transport logistics and community impact”.

Following a six-month on-site trial at its Woolton wastewater treatment works in Merseyside, United Utilities is introducing a method that uses a coagulant created from tree bark at some of its small, rural wastewater treatment facilities in the North West.

United Utilities’ principal engineer, Callum Grundy, explained the importance of the project, saying: “We are exploring a range of different technologies and methods that enhance phosphorus removal and reduce reliance on chemical dosing. This trial has delivered fantastic outcomes, and we are incredibly excited that we are now introducing solutions based on natural coagulants more widely across our region.

“The extensive research means we now understand the capacity for phosphorus removal, the ideal site characteristics and how best to implement them.

Grundy added: “Innovative approaches such as this support the water sector’s drive to embed more sustainable treatment processes. They help us increase resilience, deliver financial and carbon savings and help maintain compliance, which will ultimately mean a cleaner environment.”

Following the trial, United Utilities is working closely with provider Veolia Water Technologies to fast-track the introduction of the product.