Mobilising the MOB to improve water quality in the River Bollin

11 Mar 2024

Overview

Macclesfield Wastewater Treatment Works at Prestbury discharges cleaned water into the River Bollin, a major tributary of the River Mersey, which rises in the forest of Macclesfield on the edge of the Peak District.

Challenge

Investment was needed to lower phosphorus and ammonia levels and to improve the quality of the cleaned water released back into the environment during periods of heavy rainfall. An additional challenge was to install these new processes while continuing to run the existing treatment works and avoiding impact to residents.

Solution

This £50m project adds a storm surge storage tank at the site and introduces a new process called Mobile Organic Biofilm™ (MOB™), an innovative biological approach that uses renewable plant material to support the growth of the bacteria we use to treat wastewater.

Outcome

The additional capacity will meet the needs of the forecasted increase in population. Improvements to the process will improve water quality and reduce ammonia and phosphorus discharges.

These improvement form part of our commitment to creating better rivers, investing £420 million to reduce spills from 63 storm overflows in Cheshire, part of our proposed £13.7 billion investment to make a stronger, greener, healthier North West.

Back to Case Studies