United Utilities begins £50m investment to improve River Bollin through innovative wastewater treatment process

A £50 million investment at Macclesfield Wastewater Treatment Works (WwTW) will use an innovative process to help improve water quality in the River Bollin.

The project, being undertaken by United Utilities at its site in Prestbury, will mean lower phosphorus and ammonia levels in the treated water that is released from the works back into the environment. The stricter targets, being introduced from the end of 2024, are driven by the Water Framework Directive (WFD).

To meet these lower nutrient limits, the innovative Nuvoda Mobile Organic Biofilm™ (MOB™) process is being introduced for the first time at a United Utilities wastewater treatment works. This biological approach uses a renewable plant material as a carrier to support the growth of the bacteria we use to treat the wastewater. It has a number of benefits alongside being the lowest whole life cost solution for the site - it will do this in a smaller footprint, using a plant-based media rather than plastic media along with providing part of a wider solution that will allow us to remove phosphorus using biology rather than using chemicals. United Utilities will be the first UK water company to install the novel process which was offered to us by our construction delivery partner, C2V+.

The investment at Macclesfield WwTW will also provide additional treatment capacity to meet the needs of a growing population, with monitoring of flows and stormwater discharges continuing.

Alison Byrne, Project Manager at United Utilities, said: “At United Utilities we don’t just supply high quality water and treat wastewater – we also want to make our region greener, healthier, and stronger.

“Investing in our wastewater treatment works is a vital part of that goal, and the project at Macclesfield will ensure we can continue to treat wastewater to the highest standards and help protect our local waterways.

“It’s a challenging project as we have to ensure the new processes are installed offline while continuing to run the existing treatment works, but it’ll all be done within the current site footprint and with minimal impact to local residents.”

The water company recently showed Macclesfield MP David Rutley and representatives from Mottram St Andrews Fly Fishing Club around the wastewater treatment works and highlighted how the site’s facilities are going to be upgraded. During the visit United Utilities also explained how a broad range of sectors with expertise and influence are working together to help continue to improve the health of the wider River Bollin catchment area.

Asked about what he thought of the investment work, David Rutley MP said: “It is positive to see United Utilities making a significant £50 million investment to upgrade Macclesfield’s Wastewater Treatment Works. Using innovative new technology the project will help ensure that the water is treated to high standards and improve the water quality in the River Bollin. I welcome this important investment and will continue to work with United Utilities on this and other initiatives to help improve the environment in our area and beyond.”

Earlier this year United Utilities published its ‘Better Rivers, Better North West’ programme, outlining a £230 million investment plan to improve 184km of the region’s rivers. Find out more at: www.unitedutilities.com/corporate/newsroom/latest-news/united-utilities-publishes-road-map-to-better-river-health/