A total of £50 million is to be invested at Macclesfield Wastewater Treatment Works (WwTW).

The investment will use innovative technology to help improve water quality in the River Bollin.

The project, being undertaken by United Utilities at its site in Prestbury, will mean lower phosphorous 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, innovative Nuvoda Mobile Organic Biofilm (MOB) technology is being introduced for the first time at a United Utilities wastewater treatment works. This biological approach uses a highly renewable plant material to digest the sludge produced in the treatment process. It has a number of benefits, helping to optimise the wastewater treatment process, increase capacity, and improve nutrient removal, as well as being friendlier for the environment.


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

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.